Science.gov

Sample records for intensity interferometry experiments

  1. Signal-to-noise ratio of intensity interferometry experiments with highly asymmetric x-ray sources

    SciTech Connect

    Feng, Y.P.; McNulty, I.; Xu, Z.; Gluskin, E.

    1995-06-23

    The authors discuss the signal-to-noise ratio of an intensity interferometry experiment for a highly asymmetric x-ray source using different aperture shapes in front of the photodetectors. It is argued that, under ideal conditions using noiseless detectors and electronics, the use of slit-shaped apertures, whose widths are smaller but whose lengths are much greater than the transverse coherence widths of the beam in the corresponding directions, provides no signal-to-noise advantage over the use of pinhole apertures equal to or smaller than the coherence area. As with pinholes, the signal-to-noise ratio is determined solely by the count degeneracy parameter and the degree of coherence of the beam. This contrasts with the signal-to-noise ratio enhancement achievable using slit-shaped apertures with an asymmetric source in a Young`s experiment.

  2. Signal-to-noise ratio of intensity interferometry experiments with highly asymmetric x-ray sources

    SciTech Connect

    Feng, Y.P.; McNulty, I.; Xu, Z.; Gluskin, E.

    1997-02-11

    We discuss the signal-to-noise ratio of an intensity interferometry experiment for a highly asymmetric x-ray source using different aperture shapes in front of the photodetectors. It is argued that, under ideal conditions using noiseless detectors and electronics, the use of slit-shaped apertures, whose widths are smaller but whose lengths are much greater than the transverse coherence widths of the beam in the corresponding directions, provides no signal-to-noise advantage over the use of pinhole apertures equal to or smaller than the coherence area. As with pinholes, the signal-to-noise ratio is determined solely by the count degeneracy parameter and the degree of coherence of the beam. This contrasts with the signal-to-noise ratio enhancement achievable using slit-shaped apertures with an asymmetric source in a Young`s experiment.

  3. Stellar Temporal Intensity Interferometry

    NASA Astrophysics Data System (ADS)

    Kian, Tan Peng

    Stellar intensity interferometry was developed by Hanbury-Brown & Twiss [1954, 1956b, 1957, 1958] to bypass the diffraction limit of telescope apertures, with successful measurements including the determination of 32 stellar angular diameters using the Narrabri Stellar Intensity Interferometer [Hanbury-Brown et al., 1974]. This was achieved by measuring the intensity correlations between starlight received by a pair of telescopes separated by varying baselines b which, by invoking the van Cittert-Zernicke theorem [van Cittert, 1934; Zernicke, 1938], are related to the angular intensity distributions of the stellar light sources through a Fourier transformation of the equal-time complex degree of coherence gamma(b) between the two telescopes. This intensity correlation, or the second order correlation function g(2) [Glauber, 1963], can be described in terms of two-photoevent coincidence measurements [Hanbury-Brown, 1974] for our use of photon-counting detectors. The application of intensity interferometry in astrophysics has been largely restricted to the spatial domain but not found widespread adoption due to limitations by its signal-to-noise ratio [Davis et al., 1999; Foellmi, 2009; Jensen et al., 2010; LeBohec et al., 2008, 2010], although there is a growing movement to revive its use [Barbieri et al., 2009; Capraro et al., 2009; Dravins & Lagadec, 2014; Dravins et al., 2015; Dravins & LeBohec, 2007]. In this thesis, stellar intensity interferometry in the temporal domain is investigated instead. We present a narrowband spectral filtering scheme [Tan et al., 2014] that allows direct measurements of the Lorentzian temporal correlations, or photon bunching, from the Sun, with the preliminary Solar g(2)(tau = 0) = 1.3 +/- 0.1, limited mostly by the photon detector response [Ghioni et al., 2008], compared to the theoretical value of g(2)(0) = 2. The measured temporal photon bunching signature of the Sun exceeded the previous records of g(2)(0) = 1.03 [Karmakar et al

  4. A new look on Intensity Interferometry

    NASA Astrophysics Data System (ADS)

    Nunez, Paul; Le Bohec, Stephan; Kieda, David; Holmes, Richard

    2009-05-01

    Intensity interferometry was introduced in the 1950's and implemented in the late 1960's with the Narrabri Interferometer. Very high angular resolution at visible wavelengths made it possible to measure stellar diameters of a few milli-arc-seconds. Air Cherenkov telescope arrays used for high energy gammaray astronomy can provide perfect sites for a revival of Intensity Interferometry in the optical region. Also, improvements in technology make the implementation of Intensity Interferometry easier and can improve sensitivity. Novel ideas on phase recovery also make it possible to reconstruct high resolution optical images of astrophysical objects in a model independent way. The capabilities and limitations of modern intensity interferometry are discussed.

  5. Photon intensity interferometry with multidetectors

    NASA Astrophysics Data System (ADS)

    Badalà, A.; Barbera, R.; Palmeri, A.; Pappalardo, G. S.; Riggi, F.; Russo, A. C.; Russo, G.; Turrisi, R.

    1994-12-01

    The technique of two-photon interferometry in heavy ion collisions at the intermediate energies is discussed and the importance of a new methodology, used in the treatment of the experimental data, is evidenced. For the first time, both the relative momentum, qrel, and the relative energy, q0, of the two correlated photons have been simultaneously used to extract the source size and lifetime of the emitting source. As an application, the performances of the BaF 2 ball of the MEDEA multidetector as a photon intensity interferometer have been evaluated. The response of such a detector to correlated pairs of photons has been studied through full GEANT3 simulations. The effects of the experimental filter on the photon correlation function have been investigated, and the noise, induced in the correlation signal by cosmic radiation, neutral pion decay, and γ-conversion, has also been estimated.

  6. Intensity Interferometry for the 21ST Century

    NASA Astrophysics Data System (ADS)

    Horch, E. P.; van Belle, G.; Genet, R. M.; Holenstein, B. D.

    Advances in detector technology and electronic timing capabilities in recent years have resulted in a new opportunity for ultra-high resolution in astronomy using intensity interferometry. We have been working with this technology and describe here the potential as we see it. Two separate opportunities exist at present: the use of Single Photon Avalanche Diode (SPAD) detectors with existing research-grade telescopes and photomultipliers coupled with light bucket telescopes. In the future, there may also be potential for space-based intensity interferometry. While intensity interferometry is not likely to replace amplitude-based interferometry, it does have certain advantages in terms of portability, use of large baselines, narrow-band imaging, and imaging in the blue. We see a new possibility for its use particularly in stellar astrophysics for these reasons.

  7. Intensity interferometry: optical imaging with kilometer baselines

    NASA Astrophysics Data System (ADS)

    Dravins, Dainis

    2016-07-01

    Optical imaging with microarcsecond resolution will reveal details across and outside stellar surfaces but requires kilometer-scale interferometers, challenging to realize either on the ground or in space. Intensity interferometry, electronically connecting independent telescopes, has a noise budget that relates to the electronic time resolution, circumventing issues of atmospheric turbulence. Extents up to a few km are becoming realistic with arrays of optical air Cherenkov telescopes (primarily erected for gamma-ray studies), enabling an optical equivalent of radio interferometer arrays. Pioneered by Hanbury Brown and Twiss, digital versions of the technique have now been demonstrated, reconstructing diffraction-limited images from laboratory measurements over hundreds of optical baselines. This review outlines the method from its beginnings, describes current experiments, and sketches prospects for future observations.

  8. A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

    SciTech Connect

    Feister, S. Orban, C.; Nees, J. A.; Morrison, J. T.; Frische, K. D.; Chowdhury, E. A.; Roquemore, W. M.

    2014-11-15

    Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

  9. CURIE: Cubesat Radio Interferometry Experiment

    NASA Astrophysics Data System (ADS)

    Sundkvist, D. J.; Saint-Hilaire, P.; Bain, H. M.; Bale, S. D.; Bonnell, J. W.; Hurford, G. J.; Maruca, B.; Martinez Oliveros, J. C.; Pulupa, M.

    2016-12-01

    The CUbesat Radio Interferometry Experiment (CURIE) is a proposed two-element radio interferometer, based on proven and developed digital radio receivers and designed to fit within a Cubesat platform. CURIE will launch as a 6U Cubesat and then separate into two 3U Cubesats once in orbit. CURIE measures radio waves from 0.1-19MHz, which must be measured from space, as those frequencies fall below the cutoff imposed by Earth's ionosphere. The principal science objective for CURIE is to use radio interferometry to study radio burst emissions from solar eruptive events such as flares and coronal mass ejections (CMEs) in the inner heliosphere, providing observations important for our understanding of the heliospheric space weather environment. The influence of space weather can be felt at Earth and other planets, as radiation levels increase and lead to auroral activity and geomagnetic effects. CURIE will be able to determine the location and size of radio burst source regions and then to track their movement outward from the Sun. In addition to the primary objective CURIE will measure the gradients of the local ionospheric density and electron temperature on the spatial scale of a few kilometers, as well as create an improved map of the radio sky at these unexplored frequencies. A space based radio interferometry observatory has long been envisioned, in orbit around the Earth or the Moon, or on the far side of the Moon. Beyond its important science objectives, CURIE will prove that the concept of a dedicated space-based interferometer can be realized by using relatively cheap Cubesats. CURIE will therefore not only provide new important science results but also serve as a pathfinder in the development of new space-based radio observation techniques for helio- and astro-physics.

  10. Phase difference enhancement with classical intensity interferometry

    NASA Astrophysics Data System (ADS)

    Shirai, Tomohiro

    2016-12-01

    It is demonstrated theoretically and experimentally that, as a novel function of classical intensity interferometry, a phase difference distribution recorded in the form of an interferogram can be enhanced by a factor of 2 on the basis of the classical intensity correlation. Such phase difference enhancement which is also referred to as phase difference amplification is, in general, known to be practically important since it increases sensitivity and accuracy in interferometric measurements. The method proposed in this study prevails over the existing methods in the sense that it can be readily implemented without difficulty in comparison with all other methods so far proposed, although the phase difference enhancement is limited to a factor of 2 in our method and thus so is the improvement of sensitivity and accuracy.

  11. Virtual Reference Interferometry: Theory & Experiment

    NASA Astrophysics Data System (ADS)

    Galle, Michael Anthony

    This thesis introduces the idea that a simulated interferogram can be used as a reference for an interferometer. This new concept represents a paradigm shift from the conventional thinking, where a reference is the phase of a wavefront that traverses a known path. The simulated interferogram used as a reference is called a virtual reference. This thesis develops the theory of virtual reference interferometry and uses it for the characterization of chromatic dispersion in short length (<1m) fibers and optical components. Characterization of chromatic dispersion on short length fiber and optical components is a very difficult challenge. Accurate measurement of first and second order dispersion is important for applications from optical component design to nonlinear photonics, sensing and communications. Techniques for short-length dispersion characterization are therefore critical to the development of many photonic systems. The current generation of short-length dispersion measurement techniques are either easy to operate but lack sufficient accuracy, or have sufficient accuracy but are difficult to operate. The use of a virtual reference combines the advantages of these techniques so that it is both accurate and easy to operate. Chromatic dispersion measurements based on virtual reference interferometry have similar accuracy as the best conventional measurement techniques due to the ability to measure first and second order dispersion directly from the interference pattern. Unique capabilities of virtual reference interferometry are demonstrated, followed by a derivation of the operational constraints and system parameters. The technique is also applied to the characterization of few-mode fibers, a hot topic in telecommunications research where mode division multiplexing promises to expand network bandwidth. Also introduced is the theory of dispersive virtual reference interferometry, which can be used to overcome the bandwidth limitations associated with the

  12. Temporal intensity interferometry for characterization of very narrow spectral lines

    NASA Astrophysics Data System (ADS)

    Tan, P. K.; Kurtsiefer, C.

    2017-08-01

    Some stellar objects exhibit very narrow spectral lines in the visible range additional to their blackbody radiation. Natural lasing has been suggested as a mechanism to explain narrow lines in Wolf-Rayet stars. However, the spectral resolution of conventional astronomical spectrographs is still about two orders of magnitude too low to test this hypothesis. We want to resolve the linewidth of narrow spectral emissions in starlight. A combination of spectral filtering with single-photon-level temporal correlation measurements breaks the resolution limit of wavelength-dispersing spectrographs by moving the linewidth measurement into the time domain. We demonstrate in a laboratory experiment that temporal intensity interferometry can determine a 20-MHz-wide linewidth of Doppler-broadened laser light and identify a coherent laser light contribution in a blackbody radiation background.

  13. A high-speed, reconfigurable, channel- and time-tagged photon arrival recording system for intensity-interferometry and quantum optics experiments

    NASA Astrophysics Data System (ADS)

    Girish, B. S.; Pandey, Deepak; Ramachandran, Hema

    2017-08-01

    We present a compact, inexpensive multichannel module, APODAS (Avalanche Photodiode Output Data Acquisition System), capable of detecting 0.8 billion photons per second and providing real-time recording on a computer hard-disk, of channel- and time-tagged information of the arrival of upto 0.4 billion photons per second. Built around a Virtex-5 Field Programmable Gate Array (FPGA) unit, APODAS offers a temporal resolution of 5 nanoseconds with zero deadtime in data acquisition, utilising an efficient scheme for time and channel tagging and employing Gigabit ethernet for the transfer of data. Analysis tools have been developed on a Linux platform for multi-fold coincidence studies and time-delayed intensity interferometry. As illustrative examples, the second-order intensity correlation function ( g 2) of light from two commonly used sources in quantum optics —a coherent laser source and a dilute atomic vapour emitting spontaneously, constituting a thermal source— are presented. With easy reconfigurability and with no restriction on the total record length, APODAS can be readily used for studies over various time scales. This is demonstrated by using APODAS to reveal Rabi oscillations on nanosecond time scales in the emission of ultracold atoms, on the one hand, and, on the other hand, to measure the second-order correlation function on the millisecond time scales from tailored light sources. The efficient and versatile performance of APODAS promises its utility in diverse fields, like quantum optics, quantum communication, nuclear physics, astrophysics and biology.

  14. Resolving microstructures in Z pinches with intensity interferometry

    SciTech Connect

    Apruzese, J. P.; Kroupp, E.; Maron, Y.; Giuliani, J. L.; Thornhill, J. W.

    2014-03-15

    Nearly 60 years ago, Hanbury Brown and Twiss [R. Hanbury Brown and R. Q. Twiss, Nature 178, 1046 (1956)] succeeded in measuring the 30 nrad angular diameter of Sirius using a new type of interferometry that exploited the interference of photons independently emitted from different regions of the stellar disk. Its basis was the measurement of intensity correlations as a function of detector spacing, with no beam splitting or preservation of phase information needed. Applied to Z pinches, X pinches, or laser-produced plasmas, this method could potentially provide spatial resolution under one micron. A quantitative analysis based on the work of Purcell [E. M. Purcell, Nature 178, 1449 (1956)] reveals that obtaining adequate statistics from x-ray interferometry of a Z-pinch microstructure would require using the highest-current generators available. However, using visible light interferometry would reduce the needed photon count and could enable its use on sub-MA machines.

  15. Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

    SciTech Connect

    Abbott, Robert; Knox, Hunter Anne; James, Stephanie; Lee, Rebekah; Cole, Chris

    2016-01-01

    We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

  16. Intensity interferometry with Aqueye+ and Iqueye in Asiago

    NASA Astrophysics Data System (ADS)

    Zampieri, Luca; Naletto, Giampiero; Barbieri, Cesare; Barbieri, Mauro; Verroi, Enrico; Umbriaco, Gabriele; Favazza, Paolo; Lessio, Luigi; Farisato, Giancarlo

    2016-08-01

    Since a number of years our group is engaged in the design, construction and operation of instruments with very high time resolution in the optical band for applications to Quantum Astronomy and more conventional Astrophysics. Two instruments were built to perform photon counting with sub-nanosecond temporal accuracy. The first of the two, Aqueye+, is regularly mounted at the 1.8 m Copernicus telescope in Asiago, while the second one, Iqueye, was mounted at the ESO New Technology Telescope in Chile, and at the William Herschel Telescope and Telescopio Nazionale Galileo on the Roque (La Palma, Canary Islands). Both instruments deliver extraordinarily accurate results in optical pulsar timing. Recently, Iqueye was moved to Asiago to be mounted at the 1.2 m Galileo telescope to attempt, for the first time ever, experiments of optical intensity interferometry (à la Hanbury Brown and Twiss) on a baseline of a few kilometers, together with the Copernicus telescope. This application was one of the original goals for the development of our instrumentation. To carry out these measurements, we are experimenting a new way of coupling the instruments to the telescopes, by means of moderate-aperture, low-optical-attenuation multi-mode optical fibers with a double-clad design. Fibers are housed in dedicated optical interfaces attached to the focus of another instrument of the 1.8 m telescope (Aqueye+) or to the Nasmyth focus of the 1.2 m telescope (Iqueye). This soft-mount solution has the advantage to facilitate the mounting of the photon counters, to keep them under controlled temperature and humidity conditions (reducing potential systematics related to varying ambient conditions), and to mitigate scheduling requirements. Here we will describe the first successful implementation of the Asiago intensity interferometer and future plans for improving it.

  17. Phonon counting and intensity interferometry of a nanomechanical resonator.

    PubMed

    Cohen, Justin D; Meenehan, Seán M; MacCabe, Gregory S; Gröblacher, Simon; Safavi-Naeini, Amir H; Marsili, Francesco; Shaw, Matthew D; Painter, Oskar

    2015-04-23

    In optics, the ability to measure individual quanta of light (photons) enables a great many applications, ranging from dynamic imaging within living organisms to secure quantum communication. Pioneering photon counting experiments, such as the intensity interferometry performed by Hanbury Brown and Twiss to measure the angular width of visible stars, have played a critical role in our understanding of the full quantum nature of light. As with matter at the atomic scale, the laws of quantum mechanics also govern the properties of macroscopic mechanical objects, providing fundamental quantum limits to the sensitivity of mechanical sensors and transducers. Current research in cavity optomechanics seeks to use light to explore the quantum properties of mechanical systems ranging in size from kilogram-mass mirrors to nanoscale membranes, as well as to develop technologies for precision sensing and quantum information processing. Here we use an optical probe and single-photon detection to study the acoustic emission and absorption processes in a silicon nanomechanical resonator, and perform a measurement similar to that used by Hanbury Brown and Twiss to measure correlations in the emitted phonons as the resonator undergoes a parametric instability formally equivalent to that of a laser. Owing to the cavity-enhanced coupling of light with mechanical motion, this effective phonon counting technique has a noise equivalent phonon sensitivity of 0.89 ± 0.05. With straightforward improvements to this method, a variety of quantum state engineering tasks using mesoscopic mechanical resonators would be enabled, including the generation and heralding of single-phonon Fock states and the quantum entanglement of remote mechanical elements.

  18. Laboratory demonstration of Stellar Intensity Interferometry using a software correlator

    NASA Astrophysics Data System (ADS)

    Matthews, Nolan; Kieda, David

    2017-06-01

    In this talk I will present measurements of the spatial coherence function of laboratory thermal (black-body) sources using Hanbury-Brown and Twiss interferometry with a digital off-line correlator. Correlations in the intensity fluctuations of a thermal source, such as a star, allow retrieval of the second order coherence function which can be used to perform high resolution imaging and source geometry characterization. We also demonstrate that intensity fluctuations between orthogonal polarization states are uncorrelated but can be used to reduce systematic noise. The work performed here can readily be applied to existing and future Imaging Air-Cherenkov telescopes to measure spatial properties of stellar sources. Some possible candidates for astronomy applications include close binary star systems, fast rotators, Cepheid variables, and potentially even exoplanet characterization.

  19. The potential for intensity interferometry with {gamma}-ray telescope arrays

    SciTech Connect

    Wit, W. J. de; Hinton, J. A.; White, R. J.; Daniel, M. K.; Le Bohec, S.; Holder, J.

    2008-02-22

    Intensity interferometry exploits a quantum optical effect in order to measure objects with extremely small angular scales. The first experiment to use this technique was the Narrabri intensity interferometer, which was successfully used in the 1970s to measure 32 stellar diameters at optical wavelengths; some as small as 0.4 milli-arcseconds. The advantage of this technique, in comparison with Michelson interferometers, is that it requires only relatively crude, but large, light collectors equipped with fast (nanosecond) photon detectors. Ground-based {gamma}-ray telescope arrays have similar specifications, and a number of these observatories are now operating worldwide, with more extensive installations planned for the future. These future instruments (CTA, AGIS, completion 2015) with 30-90 telescopes will provide 400-4000 different baselines that range in length between 50 m and a kilometre. Intensity interferometry with such arrays of telescopes attains 50 {mu}-arcsecond resolution for a limiting m{sub v}{approx}8.5. Phase information can be extracted from the interferometric measurement with phase closure, allowing image reconstruction. This technique opens the possibility of a wide range of studies amongst others, probing the stellar surface activity and the dynamic AU scale circumstellar environment of stars in various crucial evolutionary stages. Here we focuse on the astrophysical potential of an intensity interferometer utilising planned new {gamma}-ray instrumentation.

  20. Results of 1993 Repeat-Pass SAR Interferometry Experiments

    NASA Technical Reports Server (NTRS)

    Klein, J. D.; Hensley, S.; Madsen, S. N.; Webb, F. H.

    1994-01-01

    In this talk we present results of a repeat-pass SAR interferometry experiment performed in June 1993 near Portage, Maine. Differential GPS data accurate to +/-10cm were acquired to aid in motion compensation and geolocation of targets in the imagery. The experiment and data analysis will be discussed, and results will be shown during the presentation.

  1. Very long baseline interferometry and observations of gravitational lenses using intensity fluctuations: an analysis based on intensity autocorrelation

    NASA Astrophysics Data System (ADS)

    Borra, Ermanno F.

    2014-05-01

    A novel interferometric technique that uses the spectrum of the current fluctuations of a quadratic detector, a type of detector commonly used in Astronomy, has recently been introduced. It has major advantages with respect to classical interferometry. It can be used to observe gravitational lenses that cannot be detected with standard techniques. It can be used to carry out very long baseline interferometry. Although the original theoretical analysis, that uses wave interaction effects, is rigorous, it is not easy to understand. The present article therefore carries out a simpler analysis, using the autocorrelation of intensity fluctuations, which is easier to understand. It is based on published experiments that were carried out to validate the original theory. The autocorrelation analysis also validates simple numerical techniques, based on the autocorrelation, to model the angular intensity distribution of a source. The autocorrelation technique also allows a much simpler detection of the signal. In practice, the gravitational lens applications are the ones that can readily be done with presently available telescopes. We describe a practical example that shows that presently available VLBI radio-astronomical data can be used to observe microlensisng and millilensing in macrolensed Quasars. They may give information on the dark matter substructures in the lensing galaxies.

  2. Interferometry

    NASA Technical Reports Server (NTRS)

    Ridgway, Stephen; Wilson, Robert W.; Begelman, Mitchell C.; Bender, Peter; Burke, Bernard F.; Cornwell, Tim; Drever, Ronald; Dyck, H. Melvin; Johnston, Kenneth J.; Kibblewhite, Edward

    1991-01-01

    The following recommended programs are reviewed: (1) infrared and optical interferometry (a ground-based and space programs); (2) compensation for the atmosphere with adaptive optics (a program for development and implementation of adaptive optics); and (3) gravitational waves (high frequency gravitational wave sources (LIGO), low frequency gravitational wave sources (LAGOS), a gravitational wave observatory program, laser gravitational wave observatory in space, and technology development during the 1990's). Prospects for international collaboration and related issues are also discussed.

  3. Rescattering effects on intensity interferometry and initial conditions in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Li, Yang

    The properties of the quark-gluon plasma are being thoroughly studied by utilizing relativistic heavy ion collisions. After its invention in astronomy in the 1950s, intensity interferometry was found to be a robust method to probe the spatial and temporal information of the nuclear collisions also. Although rescattering effects are negligible in elementary particle collisions, it may be very important for heavy ion collisions at RHIC and in the future LHC. Rescattering after production will modify the measured correlation function and make it harder to extract the dynamical information from data. To better understand the data which are dimmed by this final state process, we derive a general formula for intensity interferometry which can calculate rescattering effects easily. The formula can be used both non-relativistically and relativistically. Numerically, we found that rescattering effects on kaon interferometry for RHIC experiments can modify the measured ratio of the outward radius to the sideward radius, which is a sensitive probe to the equation of state, by as large as 15%. It is a nontrivial contribution which should be included to understand the data more accurately. The second part of this thesis is on the initial conditions in relativistic heavy ion collisions. Although relativistic hydrodynamics is successful in explaining many aspects of the data, it is only valid after some finite time after nuclear contact. The results depend on the choice of initial conditions which, so far, have been very uncertain. I describe a formula based on the McLerran-Venugopalan model to compute the initial energy density. The soft gluon fields produced immediately after the overlap of the nuclei can be expanded as a power series of the proper time t. Solving Yang-Mills equations with color current conservation can give us the analytical formulas for the fields. The local color charges on the transverse plane are stochastic variables and have to be taken care of by random

  4. A daylight experiment for teaching stellar interferometry

    NASA Astrophysics Data System (ADS)

    Illarramendi, M. A.; Hueso, R.; Zubia, J.; Aldabaldetreku, G.; Durana, G.; Sánchez-Lavega, A.

    2014-07-01

    We discuss the design of a simple experiment that reproduces the operation of the Michelson stellar interferometer. The emission of stellar sources has been simulated using light emerging from circular end-faces of step-index polymer optical fibers and from diffuse reflections of laser beams. Interference fringes have been acquired using a digital camera, coupled to a telescope obscured by a double aperture lid. The experiment is analogous to the classical determination of stellar sizes by Michelson and can be used during the day. Using this experimental set-up, we can determine the size of extended sources, located at a distance of about 75 m from our telescope, with errors less than 25%.

  5. Single-Photon Intensity Interferometry (SPIIFy): utilizing available telescopes

    NASA Astrophysics Data System (ADS)

    Pilyavsky, Genady; Mauskopf, Philip; Smith, Nathan; Schroeder, Edward; Sinclair, Adrian; van Belle, Gerard T.; Hinkel, Natalie; Scowen, Paul

    2017-05-01

    One of the main scientific goals of optical interferometers is to measure the angular diameters of stars. These measurements, combined with precise distance measurements, such as those from the upcoming Gaia satellite, can provide improved constraints on stellar linear diameters and effective temperature. We describe a modular intensity interferometer system using commercially available single-photon detectors. We present our calculations on the sensitivity and uv-plane coverage using these modules mounted on existing telescopes on Kitt Peak, Arizona. Determining accurate stellar properties is important for testing models of stellar evolution as well as for deriving physical properties of transiting exoplanets. Our simulations indicate that we should be able to measure stellar diameters of bright stars with AB magnitude ≤6 with a precision of ≥5 per cent in a single night of observation.

  6. Neutrino Intensity Interferometry: Measuring Protoneutron Star Radii During Core-Collapse Supernovae

    NASA Astrophysics Data System (ADS)

    Wright, Warren P.; Kneller, James P.

    2017-08-01

    Intensity interferometry is a technique that has been used to measure the size of sources ranging from the quark-gluon plasma formed in heavy ion collisions to the radii of stars. We investigate using the same technique to measure protoneutron star (PNS) radii with the neutrino signal received from a core-collapse supernovae. Using a full wave-packet analysis, including the neutrino mass for the first time, we derive criteria where the effect can be expected to provide the desired signal, and find that neutrinos from the next Galactic supernova should contain extractable PNS radius information.

  7. Cramer-Rao lower bound and object reconstruction performance evaluation for intensity interferometry

    NASA Astrophysics Data System (ADS)

    Dolne, Jean J.; Gerwe, David R.; Crabtree, Peter N.

    2014-07-01

    This paper addresses the fundamental performance limits of object reconstruction methods using intensity interferometry measurements. It shows examples of reconstructed objects obtained with the FIIRE (Forward-model Interferometry Image Reconstruction Estimator) code developed by Boeing for AFRL. It considers various issues when calculating the multidimensional Cramér-Rao lower bound (CRLB) when the Fisher information matrix (FIM) is singular. In particular, when comparing FIIRE performance, characterized as the root mean square difference between the estimated and pristine objects with the CRLB, we found that FIIRE performance improved as the singularity became worse, a result not expected. We found that for invertible FIM, FIIRE yielded lower root mean squared error than the square root of the CRLB (by a factor as large as 100). This may be due to various regularization constraints (positivity, support, sharpness, and smoothness) included in FIIRE, rendering it a biased estimator, as opposed to the unbiased CRLB framework used. Using the sieve technique to mitigate false high frequency content inherent in point-by-point object reconstruction methods, we also show further improved FIIRE performance on some generic objects. It is worth noting that since FIIRE is an iterative algorithm searching to arrive at an object estimate consistent with the collected data and various constraints, an initial object estimate is required. In our case, we used a completely random initial object guess consisting of a 2-D array of uniformly distributed random numbers, sometimes multiplied with a 2-D Gaussian function.

  8. Equation of state of strongly interacting matter and intensity interferometry of thermal photons

    NASA Astrophysics Data System (ADS)

    De, Somnath; Srivastava, Dinesh K.; Chatterjee, Rupa

    2011-07-01

    We find that an equation of state (EOS) for hot hadronic matter consisting of all mesons (baryons) having M < 1.5 (2.0)GeV along with Hagedorn resonances in thermal and chemical equilibrium, matches rather smoothly with lattice EOS (p4 action, Nτ = 8) for T up to ≈200 MeV, when corrections are made for the finite volume of hadrons. Two equations of state, HHL and HHB are constructed where the above is matched to the lattice and bag model EoS respectively at a critical temperature Tc = 165MeV. We find that the particle and thermal photon spectra differ only marginally for the two equations of state at both RHIC and LHC energies. The intensity interferometry results, specially the outward correlations for thermal photons are found to be quite distinct for the two equations of state.

  9. Amplitude and intensity interferometry using satellite LNB receivers for innovative and low cost microwave and millimetre wave sensor development

    NASA Astrophysics Data System (ADS)

    Salmon, Neil A.; Wilkinson, Peter N.; Radiven, Joel

    2012-10-01

    Satellite Low Noise Block-down convertors (LNBs) have been evaluated for use in amplitude and intensity interferometry. LNBs have been found to have a high performance to cost ratio which is beneficial for any sensor system. They are investigated here for a diversity of applications from the derisking of subsystems for next generation aperture synthesis imagers having hundreds of channels [1] to a platform for the investigation of phase recovery in intensity interferometry and experimentation in entangled photons. Measured noise temperatures of LNBs were found to lie between 170 K and 300 K which is higher than typical manufacturers' specifications. A twin channel interferometer system was developed using satellite receiver feeds and LNBs at the front-end, other amplifiers, mixers, filters and local oscillators at intermediate stages, and 8-bit USB ADCs sampling synchronously at 100 MHz and a PC for data processing. LabVIEW was used to digitally demodulate the sampled data and process it into the first and second orders of coherence. Measurements of the first order of coherence from a standard low energy discharge lamp indicated interference fringes were commensurate with range and spacing of the two receivers and the source. The relationship between the measured first and second order of coherence agrees within the experimental error. Variations of the first and second orders of coherence with range, R, follow the relationship 1/R and 1/R2. The system has the potential for investigations into phase extraction for intensity interferometry and for the study of digital demodulation schemes for aperture synthesis amplitude interferometry with hundreds of receiver channels for next generation security screening systems. A twin, triple or quadruple channel polarimetric LNB interferometer could be used as basis for high precision investigations in to entangled photons and quantum communications.

  10. Design and experiment on a multi-functioned and programmable piezoelectric ceramic power supply with high precision for speckle interferometry

    NASA Astrophysics Data System (ADS)

    Wang, Biao; Ye, Yan; Wang, Yong-hong; Yang, En-zhen

    2016-01-01

    Speckle interferometry is a method of measuring structure's tiny deformations which requires accurate phase information of interference fringes. The phase information is acquired by micro-displacement produced by piezoelectric ceramic (PZT). In order to drive the PZT micro-displacement actuator, a multi-functioned and programmable PZT power supply with high precision is designed. Calibration experiment has been done to the PZT micro-actuator in speckle interferometry. Some experiments were also done to test its relevant characteristics. The experiment results show that it has high linearity, repeatability, stability, low ripple and can meet the requirement of the reliability and displacement accuracy in speckle interferometry.

  11. Core density gradient fluctuation measurement by differential interferometry in the helically symmetric experiment stellaratora)

    NASA Astrophysics Data System (ADS)

    Deng, C. B.; Brower, D. L.

    2012-10-01

    The interferometer system on the Helically Symmetric eXperiment (HSX) stellarator uses an expanded beam and linear detector array to realize a multichord measurement. Unlike conventional interferometry which determines the plasma phase shift with respect to a reference, directly evaluating the phase between two adjacent chords can be employed to measure the change in plasma phase with impact parameter. This approach provides a measure of the equilibrium density gradient or the density gradient fluctuations and is referred to as differential interferometry. For central chords, measurements are spatially localized due to a geometrical weighting factor and can provide information on core density gradient fluctuations. The measurement requires finite coherence between fluctuations in the two spatially offset chords. This technique is applied on the HSX stellarator to measure both broadband turbulence and coherent modes. Spatial localization is exploited to isolate core turbulence changes associated with change in magnetic configuration or heating location.

  12. Intensity interferometry and the second-order correlation function g(2) in astrophysics

    NASA Astrophysics Data System (ADS)

    Foellmi, C.

    2009-12-01

    Most observational techniques in astronomy can be understood as exploiting the various forms of the first-order correlation function g(1). As demonstrated by the Narrabri stellar intensity interferometer back in the 1960s by Hanbury Brown & Twiss, the first experiment to measure the second-order correlation function g(2), light can carry more information than simply its intensity, spectrum, and polarization. Since this experiment, theoretical and laboratory studies of non-classical properties of light have become a very active field of research, called quantum optics. Despite the variety of results in this field, astrophysics remained focused essentially on first-order coherence. In this paper, we study the possibility that quantum properties of light could be observed in cosmic sources. We provide the basic mathematical ingredients about the first and the second order correlation functions, applied to the modern context of astronomical observations. We aim at replacing the Hanbury Brown & Twiss experiment in this context, and present two fundamental limitations of an intensity interferometer: the requirement of a chaotic light source and the rapid decrease of the amount of correlated fluctuations with the surface temperature. The first of these limitations paradoxically emphasizes that the exploitation of g(2) is richer than what a modern intensity interferometer could bring and is particularly interesting for sources of nonthermal light. We also discuss new photon-counting avalanche photodiodes currently being developed in Grenoble, and their impact on limiting magnitudes of an intensity interferometer. We conclude by briefly presenting why microquasars in our galaxy and their extragalactic parents can represent an excellent first target in the optical/near-infrared where to observe nonthermal light and to test the use of g(2) in astrophysical sources.

  13. X-ray laser interferometry experiments at LLNL

    NASA Astrophysics Data System (ADS)

    Celliers, P.; Weber, F.; Da Silva, L. B.; Barbee, T. W.; Mrowka, S.; Trebes, J.

    1995-05-01

    We describe initial experiments to produce soft x-ray interferograms using a collisionally-pumped Y soft x-ray laser at 155 Å as the probe source. Successful operation of the interferometer requires tight alignment tolerances: spatial overlap of the beams to within 50 μm, and temporal overlap to within a 150 μm path difference. Beamsplitter vibrations were found to be a strong factor influencing the quality of the interferograms.

  14. Laser differential interferometry for supersonic blunt body receptivity experiments

    NASA Astrophysics Data System (ADS)

    Salyer, Terry Ray

    2002-01-01

    The laser differential interferometer is a high sensitivity (lambda/13,000 minimum detectable wavelength shift), large bandwidth (6 MHz), nonintrusive instrument ideal for low-density optical flow diagnostics. Up to one half wavelength shifts are possible with active phase compensation. With feedback control, a phase modulator stabilizes the system within the linear range. Calibrated receptivity experiments are performed in a Mach 4 quiet-flow Ludwieg tube. Laser-generated thermal spots are used as repeatable, controlled perturbations to the subsonic region behind the bow shock of both a hemispherical nose and a forward-facing cavity. Thermal spot amplitudes, spatial characteristics, and repeatability are measured. Both on-axis and off axis surveys of the subsonic region indicate damped oscillations with both blunt nose configurations. With the forward-facing cavity, a characteristic frequency based on the cavity geometry is detected. The results from both configurations correlate with nose-mounted and cavity base-mounted pressure transducer measurements, and thus remove frequency ambiguity from the pressure transducer experiments. High speed synchronous schlieren images show the thermal spot evolution and impingement at the hemispherical nose. Additionally, the thermal spot in freestream is modeled based on the experimental measurements. Quantitative comparisons with CFD simulations of these experiments show similar characteristics. CFD agreement is expected to improve with future use of the advanced thermal spot model.

  15. Optical Multi-Channel Intensity Interferometry - Or: How to Resolve O-Stars in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Trippe, Sascha; Kim, Jae-Young; Lee, Bangwon; Choi, Changsu; Oh, Junghwan; Lee, Taeseok; Yoon, Sung-Chul; Im, Myungshin; Park, Yong-Sun

    2014-12-01

    Intensity interferometry, based on the Hanbury Brown--Twiss effect, is a simple and inexpensive method for optical interferometry at microarcsecond angular resolutions; its use in astronomy was abandoned in the 1970s because of low sensitivity. Motivated by recent technical developments, we argue that the sensitivity of large modern intensity interferometers can be improved by factors up to approximately 25,000, corresponding to 11 photometric magnitudes, compared to the pioneering Narrabri Stellar Interferometer. This is made possible by (i) using avalanche photodiodes (APD) as light detectors, (ii) distributing the light received from the source over multiple independent spectral channels, and (iii) use of arrays composed of multiple large light collectors. Our approach permits the construction of large (with baselines ranging from few kilometers to intercontinental distances) optical interferometers at the cost of (very) long-baseline radio interferometers. Realistic intensity interferometer designs are able to achieve limiting R-band magnitudes as good as m_R≈14, sufficient for spatially resolved observations of main-sequence O-type stars in the Magellanic Clouds. Multi-channel intensity interferometers can address a wide variety of science cases: (i) linear radii, effective temperatures, and luminosities of stars, via direct measurements of stellar angular sizes; (ii) mass--radius relationships of compact stellar remnants, via direct measurements of the angular sizes of white dwarfs; (iii) stellar rotation, via observations of rotation flattening and surface gravity darkening; (iv) stellar convection and the interaction of stellar photospheres and magnetic fields, via observations of dark and bright starspots; (v) the structure and evolution of multiple stars, via mapping of the companion stars and of accretion flows in interacting binaries; (vi) direct measurements of interstellar distances, derived from angular diameters of stars or via the interferometric

  16. Exo-zodi detection capability of the Ground-Based European Nulling Interferometry Experiment (GENIE) instrument.

    PubMed

    Wallner, Oswald; Flatscher, Reinhold; Ergenzinger, Klaus

    2006-06-20

    The Ground-Based European Nulling Interferometry Experiment (GENIE) is intended as an Earth-based precursor for the European Darwin mission that will prepare the Darwin science program and demonstrate the required technology at system level. We propose a compact nulling interferometer design consisting of a two-telescope aperture configuration, an optional split-pupil add-on, and only four active control loops for counteracting environmentally induced disturbances. We show by simulation that the proposed instrument is able to detect, within a few minutes of observation time, exo-zodiacal dust clouds around Sunlike stars at 20 parsecs that are 20 times stronger than the local zodiacal dust cloud density.

  17. Seismic Interferometry at a Large, Dense Array: Capturing the Wavefield at the Source Physics Experiment

    NASA Astrophysics Data System (ADS)

    Matzel, E.; Mellors, R. J.; Magana-Zook, S. A.

    2016-12-01

    Seismic interferometry is based on the observation that the Earth's background wavefield includes coherent energy, which can be recovered by observing over long time periods, allowing the incoherent energy to cancel out. The cross correlation of the energy recorded at a pair of stations results in an estimate of the Green's Function (GF) and is equivalent to the record of a simple source located at one of the stations as recorded by the other. This allows high resolution imagery beneath dense seismic networks even in areas of low seismicity. The power of these inter-station techniques increases rapidly as the number of seismometers in a network increases. For large networks the number of correlations computed can run into the millions and this becomes a "big-data" problem where data-management dominates the efficiency of the computations. In this study, we use several methods of seismic interferometry to obtain highly detailed images at the site of the Source Physics Experiment (SPE). The objective of SPE is to obtain a physics-based understanding of how seismic waves are created at and scattered near the source. In 2015, a temporary deployment of 1,000 closely spaced geophones was added to the main network of instruments at the site. We focus on three interferometric techniques: Shot interferometry (SI) uses the SPE shots as rich sources of high frequency, high signal energy. Coda interferometry (CI) isolates the energy from the scattered wavefield of distant earthquakes. Ambient noise correlation (ANC) uses the energy of the ambient background field. In each case, the data recorded at one seismometer are correlated with the data recorded at another to obtain an estimate of the GF between the two. The large network of mixed geophone and broadband instruments at the SPE allows us to calculate over 500,000 GFs, which we use to characterize the site and measure the localized wavefield. This work performed under the auspices of the U.S. Department of Energy by

  18. The implementation and data analysis of an interferometer for intense short pulse laser experiments

    SciTech Connect

    Park, Jaebum; Baldis, Hector A.; Chen, Hui

    2016-01-01

    We present an interferometry setup and the detailed fringe analysis method for intense short pulse (SP) laser experiments. The interferometry scheme was refined through multiple campaigns to investigate the effects of pre-plasmas on energetic electrons at the Jupiter Laser Facility at Lawrence Livermore National Laboratory. The interferometer used a frequency doubled (${\\it\\lambda}=0.527~{\\rm\\mu}\\text{m}$) 0.5 ps long optical probe beam to measure the pre-plasma density, an invaluable parameter to better understand how varying pre-plasma conditions affect the characteristics of the energetic electrons. The hardware of the diagnostic, data analysis and example data are presented. The diagnostic setup and the analysis procedure can be employed for any other SP laser experiments and interferograms, respectively.

  19. The Canadian Hydrogen Intensity Mapping Experiment (CHIME)

    NASA Astrophysics Data System (ADS)

    Vanderlinde, Keith; Chime Collaboration

    2014-04-01

    Hydrogen Intensity (HI) mapping uses redshifted 21cm emission from neutral hydrogen as a 3D tracer of Large Scale Structure (LSS) in the Universe. Imprinted in the LSS is a remnant of the acoustic waves which propagated through the primordial plasma. This feature, the Baryon Acoustic Oscillation (BAO), has a characteristic scale of ~150 co-moving Mpc, which appears in the spatial correlation of LSS. By charting the evolution of this scale over cosmic time, we trace the expansion history of the Universe, constraining the Dark Energy equation of state as it becomes a significant component, particularly at redshifts poorly probed by current BAO surveys. In this talk I will introduce CHIME, a transit radio interferometer designed specifically for this purpose. CHIME is an ambitious new telescope, being built in British Columbia, Canada, and composed of five 20m x 100m parabolic reflectors which focus radiation in one direction (east-west) while interferometry is used to resolve beams in the other (north-south). Earth rotation sweeps them across the sky, resulting in complete daily coverage of the northern celestial hemisphere. Commissioning is underway on the 40 x 37m "Pathfinder" telescope, and the full sized 100m x 100m instrument is funded and under development.

  20. Physics prospects with an intense neutrino experiment

    NASA Astrophysics Data System (ADS)

    Solomey, Nickolas

    2000-12-01

    With new forthcoming intense neutrino beams, for the study of neutrino oscillations, it is possible to consider other physics experiments that can be done with these extreme neutrino fluxes available close to the source.

  1. The Combined Radio Interferometry and COSMIC Experiment in Tomography (CRICKET) Campaign

    NASA Astrophysics Data System (ADS)

    Dymond, Kenneth; Coker, Clayton; Bernhardt, Paul; Cohen, Aaron; Crane, Patrick; Kassim, Namir; Lazio, Joseph; Weiler, Kurt; Watts, Christopher; Rickard, Lee J.; Taylor, Greg; Schinzel, Frank; Philstrom, Ylva; Close, Sigrid; Colestock, Patrick; Myers, Steve; Datta, Abirhup

    We report on the Combined Radio Interferometry and COSMIC Experiment in Tomography Campaign (CRICKET) held on September 15 and 17, 2007. The experiment used the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC also known as FORMOSAT-3) in conjunction with the Very Large Array radio telescope, located near Socorro, NM, to study the ionosphere from the global scale down to the regional scale. Each COSMIC satellite includes three instruments capable of measuring the ionosphere: the Tiny Ionospheric Photometer (TIP), a UV radiometer; the GPS Occultation experiment (GOX), a dual-frequency GPS occultation receiver; and the Tri-band Beacon (TBB), a three frequency coherently radiating radio beacon. These three instruments have been demonstrated to be a powerful means for characterizing the global-scale ionosphere. The VLA when deployed at its largest extent and while operating at 73.8 MHz is incredibly sensitive to relative total electron content variations of the regional ionosphere over about a 30-100 km diameter area. In this work, we concentrate on the first set of observations on September 15, 2007 at approximately 0830 UT. We have successfully married these heterogeneous data sets, using a tomographic data fusion approach, to produce a consistent ionospheric specification from the global scale down to the regional scale.

  2. Image Reconstruction from Sparse Irregular Intensity Interferometry Measurements of Fourier Magnitude

    DTIC Science & Technology

    2013-09-01

    any particular geometry of the telescope array configuration. Its inputs are a list of measurements, each specified by UV coordinate and noise...the angular subtense and desired angular resolution. Fig. 2 shows the geometry of this array and the resulting baselines assuming a zenith line-of...Telescope array geometry and corresponding set of baselines for the analyzed intensity interferometer system. Fig. 3. Division of broadband

  3. On Using Intensity Interferometry for Feature Identification and Imaging of Remote Objects

    NASA Technical Reports Server (NTRS)

    Erkmen, Baris I.; Strekalov, Dmitry V.; Yu, Nan

    2013-01-01

    We derive an approximation to the intensity covariance function of two scanning pinhole detectors, facing a distant source (e.g., a star) being occluded partially by an absorptive object (e.g., a planet). We focus on using this technique to identify or image an object that is in the line-of-sight between a well-characterized source and the detectors. We derive the observed perturbation to the intensity covariance map due to the object, showing that under some reasonable approximations it is proportional to the real part of the Fourier transform of the source's photon-flux density times the Fourier transform of the object's intensity absorption. We highlight the key parameters impacting its visibility and discuss the requirements for estimating object-related parameters, e.g., its size, velocity or shape. We consider an application of this result to determining the orbit inclination of an exoplanet orbiting a distant star. Finally, motivated by the intrinsically weak nature of the signature, we study its signal-to-noise ratio and determine the impact of system parameters.

  4. Interferometry based technique for intensity profile measurements of far IR beams

    NASA Astrophysics Data System (ADS)

    Soloviev, Alexander A.; Khazanov, Efim A.; Kozhevatov, Ilya E.; Palashov, Oleg V.

    2007-06-01

    We present a novel, to the best of our knowledge, method for measuring the intensity profile of far-IR beams. The method is based on the measurements of nonstationary variation in optical thickness of a fused-silica plate heated by the studied radiation. The optical thickness is observed by means of a reflecting interferometer. Purpose-made experimental setup allows one to measure beams with an aperture of up to 60 mm with a spatial resolution of 1 mm. The accessibility of the utilized technologies and the possibility to easily increase the aperture are the major advantages of this approach. The probable area of application for the method is measurements of beams produced by powerful industrial far-IR lasers.

  5. Millimeter Wave Interferometry and Fabry-Perot Spectroscopy on the Madison Plasma Dynamo Experiment

    NASA Astrophysics Data System (ADS)

    Flanagan, K.; Clark, M.; Cooper, C.; Ding, W.; Milhone, J.; Peng, W.; Roesler, F. L.; Wallace, J.; Weisberg, D.; Forest, C. B.

    2013-10-01

    New non-invasive optical diagnostics for use on the Madison Plasma Dynamo Experiment (MPDX) allow for measurements of line-averaged density through interferometry and ion velocity and temperature through Fabry-Perot spectroscopy. Both the interferometer and the Fabry-Perot spectrometer are capable of scanning multiple chords through the plasma. Through inversion techniques, these chords can be used to construct profiles of electron density, ion temperature, and ion velocity. The interferometer consists of a millimeter wave source with two detunable outputs, two fundamental mixers with low-noise amplifiers, and an analog phase detector. A millimeter wave beam provides an easily measurable phase shift of approximately one fringe at typical MPDX densities of 1011 -1012 cm-3. The Fabry-Perot spectrometer collects light from a single chord through the plasma and passes it through an etalon, which images the typical ring structure onto a high performance CCD camera. Through a ring summing technique developed by Roesler et al., we can determine the ion velocity and temperature on both MPDX and PCX. We will present detailed descriptions of both diagnostics and their implementation on MPDX in addition to preliminary density, ion temperature, and ion velocity measurements. Work Funded by NSF and CMSO.

  6. Planetary Radio Interferometry and Doppler Experiment (PRIDE) for Planetary Atmospheric Studies

    NASA Astrophysics Data System (ADS)

    Bocanegra Bahamon, Tatiana; Cimo, Giuseppe; Duev, Dmitry; Gurvits, Leonid; Molera Calves, Guifre; Pogrebenko, Sergei

    2015-04-01

    The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that allows the determination of the radial velocity and lateral coordinates of planetary spacecraft with very high accuracy (Duev, 2012). The setup of the experiment consists of several ground stations from the European VLBI Network (EVN) located around the globe, which simultaneously perform Doppler tracking of a spacecraft carrier radio signal, and are subsequently processed in a VLBI-style in phase referencing mode. Because of the accurate examination of the changes in phase and amplitude of the radio signal propagating from the spacecraft to the multiple stations on Earth, the PRIDE technique can be used for several fields of planetary research, among which planetary atmospheric studies, gravimetry and ultra-precise celestial mechanics of planetary systems. In the study at hand the application of this technique for planetary atmospheric investigations is demonstrated. As a test case, radio occultation experiments were conducted with PRIDE having as target ESA's Venus Express, during different observing sessions with multiple ground stations in April 2012 and March 2014. Once each of the stations conducts the observation, the raw data is delivered to the correlation center at the Joint Institute for VLBI in Europe (JIVE) located in the Netherlands. The signals are processed with a high spectral resolution and phase detection software package from which Doppler observables of each station are derived. Subsequently the Doppler corrected signals are correlated to derive the VLBI observables. These two sets of observables are used for precise orbit determination. The reconstructed orbit along with the Doppler observables are used as input for the radio occultation processing software, which consists of mainly two modules, the geometrical optics module and the ray tracing inversion module, from which vertical density profiles, and subsequently, temperature and pressure profiles of Venus

  7. Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique: A test case of the Mars Express Phobos fly-by

    NASA Astrophysics Data System (ADS)

    Duev, D. A.; Pogrebenko, S. V.; Cimò, G.; Molera Calvés, G.; Bocanegra Bahamón, T. M.; Gurvits, L. I.; Kettenis, M. M.; Kania, J.; Tudose, V.; Rosenblatt, P.; Marty, J.-C.; Lainey, V.; de Vicente, P.; Quick, J.; Nickola, M.; Neidhardt, A.; Kronschnabl, G.; Ploetz, C.; Haas, R.; Lindqvist, M.; Orlati, A.; Ipatov, A. V.; Kharinov, M. A.; Mikhailov, A. G.; Lovell, J. E. J.; McCallum, J. N.; Stevens, J.; Gulyaev, S. A.; Natush, T.; Weston, S.; Wang, W. H.; Xia, B.; Yang, W. J.; Hao, L.-F.; Kallunki, J.; Witasse, O.

    2016-09-01

    Context. The closest ever fly-by of the Martian moon Phobos, performed by the European Space Agency's Mars Express spacecraft, gives a unique opportunity to sharpen and test the Planetary Radio Interferometry and Doppler Experiments (PRIDE) technique in the interest of studying planet-satellite systems. Aims: The aim of this work is to demonstrate a technique of providing high precision positional and Doppler measurements of planetary spacecraft using the Mars Express spacecraft. The technique will be used in the framework of Planetary Radio Interferometry and Doppler Experiments in various planetary missions, in particular in fly-by mode. Methods: We advanced a novel approach to spacecraft data processing using the techniques of Doppler and phase-referenced very long baseline interferometry spacecraft tracking. Results: We achieved, on average, mHz precision (30 μm/s at a 10 s integration time) for radial three-way Doppler estimates and sub-nanoradian precision for lateral position measurements, which in a linear measure (at a distance of 1.4 AU) corresponds to ~50 m.

  8. White light interferometry for quantitative surface characterization in ion sputtering experiments.

    SciTech Connect

    Baryshev, S. V.; Zinovev, A. V.; Tripa, C. E.; Erck, R. A.; Veryovkin, I. V.

    2012-07-01

    White light interferometry (WLI) can be used to obtain surface morphology information on dimensional scale of millimeters with lateral resolution as good as {approx}1 {micro}m and depth resolution down to 1 nm. By performing true three-dimensional imaging of sample surfaces, the WLI technique enables accurate quantitative characterization of the geometry of surface features and compares favorably to scanning electron and atomic force microscopies by avoiding some of their drawbacks. In this paper, results of using the WLI imaging technique to characterize the products of ion sputtering experiments are reported. With a few figures, several example applications of the WLI method are illustrated when used for (i) sputtering yield measurements and time-to-depth conversion, (ii) optimizing ion beam current density profiles, the shapes of sputtered craters, and multiple ion beam superposition and (iii) quantitative characterization of surfaces processed with ions. In particular, for sputter depth profiling experiments of {sup 25}Mg, {sup 44}Ca and {sup 53}Cr ion implants in Si (implantation energy of 1 keV per nucleon), the depth calibration of the measured depth profile curves determined by the WLI method appeared to be self-consistent with TRIM simulations for such projectile-matrix systems. In addition, high depth resolution of the WLI method is demonstrated for a case of a Genesis solar wind Si collector surface processed by gas cluster ion beam: a 12.5 nm layer was removed from the processed surface, while the transition length between the processed and untreated areas was 150 {micro}m.

  9. Spatio-temporal experiments of volume elastic objects with high speed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Pérez López, C.; Hernández Montes, M. S.; Mendoza Santoyo, F.; Gutiérrez Hernandez, D. A.

    2011-08-01

    The optical non-destructive digital holographic interferometry (DHI) technique has proven to be a powerful tool in measuring vibration phenomena with a spatial resolution ranging from a few hundreds of nanometers to tens of micrometers. With the aid of high speed digital cameras it is possible to achieve simultaneously spatial and temporal resolution, and thus capable of measuring the entire object mechanical oscillation trajectory from one to several cycles. It is important to mention that due to faster computers with large data storage capacity there is an increasing interest in applying numerical simulation methods to mimic different real life objects for example, in the field of modern elastic materials and biological systems. The complex algorithms involved cannot render significant results mainly due to the rather large number of variables. In order to test these numerical simulations some experiments using optical techniques have been designed and reported. This is very important for example in measurements of the dynamic elastic properties of materials. In this work we present some preliminary results from experiments that use DHI to measure vibrations of an elastic spherical object subject to a mechanical excitation that induces resonant vibration modes in its volume. We report on the spatial and temporal effects that by their nature have a non-linear mechanical response. The use of a high speed CMOS camera in DHI assures the measurement of this nonlinear behavior as a sum of linear effects that happen during very short time lapses and with very small displacement amplitudes. We conclude by stating that complex numerical models may be compared to results using DHI, thus proposing an alternative method to prove and verify the mathematical models vs. real measurements on volumetric elastic objects.

  10. Holograph and Interferometry.

    ERIC Educational Resources Information Center

    Altman, Thomas C.

    1992-01-01

    Describes a method to create holograms for use in different interferometry techniques. Students utilize these techniques in experiments to study the structural integrity of a clarinet reed and the effects of temperature on objects. (MDH)

  11. Astrophysically relevant hydrodynamics experiments using intense lasers

    NASA Astrophysics Data System (ADS)

    Remington, B. A.; Budil, K. S.; Estabrook, K.; Glendinning, S. G.; Gold, D.; Ryutov, D.; Kane, J.; Arnett, D.; Drake, R. P.; Smith, T.; Carroll, J.; McCray, R.; Liang, E.; Keilty, K.; Rubenchik, A.

    1998-04-01

    In a broad-based collaboration, we are developing a series of astrophysically relevant hydrodynamics experiments on the Nova and PetaWatt lasers at Lawrence Livermore National Laboratory. Issues that we are or planning to investigate are deep nonlinear hydrodynamic instabilities in 2D versus 3D, relevant to core-collapse supernova explosions [J. Kane et al., Ap. J. (1997); B.A. Remington et al., Phys. Plasmas (1997).]; strong-shock hydrodynamics relevant to supernova remnant formation [R.P. Drake et al., submitted, Ap. J. (1997).]; radiative blast wave development, of potential interest to gamma-ray burst models [E. Liang et al., 2nd Int. Workshop on LaboratoryAstrophysics using Intense Lasers, Mar. 19-21, 1998, Univ. of AZ.]; and cratering experiments, of possible interest to hypervelocity meteoroid impacts [A. Rubenchik et al., 2nd Int. Workshop on Laboratory Astrophysics using Intense Lasers, Mar. 19-21, 1998, Univ. of AZ.]. An overview of this work will be given, and the issue of scaling will be addressed [D. Ryutov et al., in preparation for submittal to Ap. J. (1998).].

  12. EPR experiment and 2-photon interferometry: Report of a 2-photon interference experiment

    NASA Technical Reports Server (NTRS)

    Shih, Y. H.; Rubin, M. H.; Sergienko, A. V.

    1992-01-01

    After a very brief review of the historical Einstein, Podolsky, and Rosen (EPR) experiments, a new two-photon interference type EPR experiment is reported. A two-photon state was generated by optical parametric down conversion. Pairs of light quanta with degenerate frequency but divergent directions of propagation were sent to two independent Michelson interferometers. First and second order interference effectors were studied. Different than other reports, we observed that the second order interference visibility vanished when the optical path difference of the interferometers were much less than the coherence length of the pumping laser beam. However, we also observed that the second order interference behaved differently depending on whether the interferometers were set at equal or different optical path differences.

  13. Review of Astrophysics Experiments on Intense Lasers

    SciTech Connect

    Remington, B A; Drake, R P; Takabe, H; Arnett, D

    2000-01-19

    Astrophysics has traditionally been pursued at astronomical observatories and on theorists' computers. Observations record images from space, and theoretical models are developed to explain the observations. A component often missing has been the ability to test theories and models in an experimental setting where the initial and final states are well characterized. Intense lasers are now being used to recreate aspects of astrophysical phenomena in the laboratory, allowing the creation of experimental testbeds where theory and modeling can be quantitatively tested against data. We describe here several areas of astrophysics--supernovae, supernova remnants, gamma-ray bursts, and giant planets--where laser experiments are under development to test our understanding of these phenomena.

  14. Recent experiments conducted with the Wide-field imaging interferometry testbed (WIIT)

    NASA Astrophysics Data System (ADS)

    Leisawitz, David T.; Juanola-Parramon, Roser; Bolcar, Matthew; Fienup, James R.; Iacchetta, Alexander S.; Maher, Stephen F.; Rinehart, Stephen A.

    2016-08-01

    The Wide-field Imaging Interferometry Testbed (WIIT) was developed at NASA's Goddard Space Flight Center to demonstrate and explore the practical limitations inherent in wide field-of-view "double Fourier" (spatio-spectral) interferometry. The testbed delivers high-quality interferometric data and is capable of observing spatially and spectrally complex hyperspectral test scenes. Although WIIT operates at visible wavelengths, by design the data are representative of those from a space-based far-infrared observatory. We used WIIT to observe a calibrated, independently characterized test scene of modest spatial and spectral complexity, and an astronomically realistic test scene of much greater spatial and spectral complexity. This paper describes the experimental setup, summarizes the performance of the testbed, and presents representative data.

  15. A small-scale experiment using microwave interferometry to investigate detonation and shock-to-detonation transition in pressed TATB

    NASA Astrophysics Data System (ADS)

    Renslow, Peter John

    A small-scale characterization test utilizing microwave interferometry was developed to dynamically measure detonation and run to detonation distance in explosives. The technique was demonstrated by conducting two experimental series on the well-characterized explosive triaminotrinitrobenzene (TATB). In the first experiment series, the detonation velocity was observed at varying porosity. The velocity during TATB detonation matched well with predictions made using CHEETAH and an empirical relation from the Los Alamos National Laboratory (LANL). The microwave interferometer also captured unsteady propagation of the reaction when a low density charge was near the failure diameter. In the second experiment series, Pop-plots were produced using data obtained from shock initiation of the TATB through a polymethyl methacrylate (PMMA) attenuator. The results compared well to wedge test data from LANL despite the microwave interferometer test being of substantially smaller scale. The results showed the test method is attractive for rapid characterization of new and improvised explosive materials.

  16. Time Delay Interferometry Experiments at the University of Florida Interferometric Simulator.

    NASA Astrophysics Data System (ADS)

    Mitryk, Shawn

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a joint NASA/ESA space mission proposed to directly measure gravitational waves in the frequency range from 30 uHz to 1 Hz. To accomplish this LISA will utilize a modified Michelson interferometer to measure the spatial changes between three drag-free proof masses in a heliocentric orbit separated by a distance of 5 Gm. In order to accurately measure the distance between the proof masses, LISA requires ultra-stable laser signals to reduce the noise in the measurement. Any additional laser noise must be recorded and extracted from the final measurement through a method known as time-delay interferometry (TDI). The University of Florida LISA Interferometry Simulator (UFLIS) has the ability to perform a hardware-in-the-loop simulation of the LISA Constellation in order to verify laser noise stabilization and extraction techniques. We present the UFLISs' capability to replicate the expected pre-stabilized laser noise, measure and delay the laser signals due to the light-travel time along the LISA arm, and inject mock gravitational wave signals. The resulting laser beatnotes are then recorded and combined based on TDI theory to extract the laser noise and recover the injected gravitational wave signals to within the requirement proposed by the LISA mission science team. This work is supported by NASA through grants BEFS 04-0019-0019 and 07 ATFP 07-0116.

  17. The Palomar kernel-phase experiment: testing kernel phase interferometry for ground-based astronomical observations

    NASA Astrophysics Data System (ADS)

    Pope, Benjamin; Tuthill, Peter; Hinkley, Sasha; Ireland, Michael J.; Greenbaum, Alexandra; Latyshev, Alexey; Monnier, John D.; Martinache, Frantz

    2016-01-01

    At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment and shape of the telescope optics. These errors can be corrected physically, with active and adaptive optics, and in post-processing of the resulting image. A recently developed adaptive optics post-processing technique, called kernel-phase interferometry, uses linear combinations of phases that are self-calibrating with respect to small errors, with the goal of constructing observables that are robust against the residual optical aberrations in otherwise well-corrected imaging systems. Here, we present a direct comparison between kernel phase and the more established competing techniques, aperture masking interferometry, point spread function (PSF) fitting and bispectral analysis. We resolve the α Ophiuchi binary system near periastron, using the Palomar 200-Inch Telescope. This is the first case in which kernel phase has been used with a full aperture to resolve a system close to the diffraction limit with ground-based extreme adaptive optics observations. Excellent agreement in astrometric quantities is found between kernel phase and masking, and kernel phase significantly outperforms PSF fitting and bispectral analysis, demonstrating its viability as an alternative to conventional non-redundant masking under appropriate conditions.

  18. Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder

    NASA Astrophysics Data System (ADS)

    Bandura, Kevin; Addison, Graeme E.; Amiri, Mandana; Bond, J. Richard; Campbell-Wilson, Duncan; Connor, Liam; Cliche, Jean-François; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gibbs, Kenneth; Gilbert, Adam; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Klages, Peter; Landecker, Tom L.; Masui, Kiyoshi; Mena Parra, Juan; Newburgh, Laura B.; Pen, Ue-li; Peterson, Jeffrey B.; Recnik, Andre; Shaw, J. Richard; Sigurdson, Kris; Sitwell, Mike; Smecher, Graeme; Smegal, Rick; Vanderlinde, Keith; Wiebe, Don

    2014-07-01

    A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ~100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ~30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.

  19. Multiple telescope infrared interferometry

    NASA Technical Reports Server (NTRS)

    Townes, C. H.; Sutton, E. C.

    1981-01-01

    The advantages of multiple telescope infrared interferometry are discussed in detail, using the 10 micron region as a specific example. Scale and seeing considerations are addressed, taking into account analytically the distorting effect of turbulent air and discussing the effect of water vapor on seeing. The usefulness of fringe phase determination to determine the intensities in the radiation field, and the effect of atmospheric fluctuations on their use, are considered. Astrometry by means of interferometry is extensively covered, with examples such as a plot of the fringe phase of o Ceti as a function of time compared with a theoretical fringe phase of the star with a fixed best-fit baseline. The sensitivity of an interferometer involving two receiving telescopes is considered. Finally, an example of a telescope design for 10-micron interferometry is described and depicted.

  20. Laser feedback interferometry based on high density cosine-like intensity fringes with phase quasi-quadrature.

    PubMed

    Zeng, Zhaoli; Zhang, Shulian; Tan, Yidong

    2013-04-22

    A novel laser feedback interferometry based on high-order feedback is presented and realized for the first time. The interferometer uses a birefringence dual frequency laser and a tilted feedback mirror with high amplitude reflectivity to generate high density cosine-like optical fringes. These optical fringes have nanoscale resolution. Particularly, phase quasi-quadrature between the dual frequency fringes is obtained because of the phase shift caused by the changes of external optical path length. This phase characteristic can be used to distinguish the direction of movement easily. Under typical room conditions, the system's resolution is 0.51nm in 850μm range, and its 2 min displacement accuracy is 5nm.

  1. Interferometry concepts

    NASA Astrophysics Data System (ADS)

    Millour, F.

    2014-09-01

    This paper serves as an introduction to the current book. It provides the basic notions of long-baseline optical/infrared interferometry prior to reading all the subsequent chapters, and is not an extended introduction to the field.

  2. Spanish Intensive Courses: The South Carolina Experience.

    ERIC Educational Resources Information Center

    Hill, David P.

    The Spanish Intensive Courses sequence at the University of South Carolina, first offered in fall 1982, has become well received and highly visible in the university. The sequence has grown to three courses in fall 1983, all exceeding minimum enrollment requirements despite selective admission criteria. The success of the sequence has inspired the…

  3. A portable laser system for high-precision atom interferometry experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, M.; Prevedelli, M.; Giorgini, A.; Tino, G. M.; Peters, A.

    2011-01-01

    We present a modular rack-mounted laser system for the cooling and manipulation of neutral rubidium atoms which has been developed for a portable gravimeter based on atom interferometry that will be capable of performing high-precision gravity measurements directly at sites of geophysical interest. This laser system is constructed in a compact and mobile design so that it can be transported to different locations, yet it still offers improvements over many conventional laboratory-based laser systems. Our system is contained in a standard 19″ rack and emits light at five different frequencies simultaneously on up to 12 fibre ports at a total output power of 800 mW. These frequencies can be changed and switched between ports in less than a microsecond. The setup includes two phase-locked diode lasers with a phase noise spectral density of less than 1 μrad/Hz1/2 in the frequency range in which our gravimeter is most sensitive to noise. We characterise this laser system and evaluate the performance limits it imposes on an interferometer.

  4. GPS Interferometry

    NASA Technical Reports Server (NTRS)

    Vangrass, Frank

    1992-01-01

    This semi-annual progress report provides an overview of the work performed during the first six months of Grant NAG 1 1423, titled 'GPS Interferometry'. The Global Positioning System (GPS) is a satellite-based positioning and timing system. Through the use of interferometric processing techniques, it is feasible to obtain sub-decimeter position accuracies for an aircraft in flight. The proposed duration of this Grant is three years. During the first year of the Grant, the efforts are focussed on two topics: (1) continued development of GPS Interferometry core technology; and (2) rapid technology demonstration of GPS interferometry through the design and implementation of a flight reference/autoland system. Multipath error has been the emphasis of the continued development of GPS Interferometry core technology. The results have been documented in a Doctoral Dissertation and a conference paper. The design and implementation of the flight reference/autoland system is nearing completion. The remainder of this progress report summarizes the architecture of this system.

  5. The TIME-Pilot intensity mapping experiment

    NASA Astrophysics Data System (ADS)

    Crites, A. T.; Bock, J. J.; Bradford, C. M.; Chang, T. C.; Cooray, A. R.; Duband, L.; Gong, Y.; Hailey-Dunsheath, S.; Hunacek, J.; Koch, P. M.; Li, C. T.; O'Brient, R. C.; Prouve, T.; Shirokoff, E.; Silva, M. B.; Staniszewski, Z.; Uzgil, B.; Zemcov, M.

    2014-08-01

    TIME-Pilot is designed to make measurements from the Epoch of Reionization (EoR), when the first stars and galaxies formed and ionized the intergalactic medium. This will be done via measurements of the redshifted 157.7 um line of singly ionized carbon ([CII]). In particular, TIME-Pilot will produce the first detection of [CII] clustering fluctuations, a signal proportional to the integrated [CII] intensity, summed over all EoR galaxies. TIME-Pilot is thus sensitive to the emission from dwarf galaxies, thought to be responsible for the balance of ionizing UV photons, that will be difficult to detect individually with JWST and ALMA. A detection of [CII] clustering fluctuations would validate current theoretical estimates of the [CII] line as a new cosmological observable, opening the door for a new generation of instruments with advanced technology spectroscopic array focal planes that will map [CII] fluctuations to probe the EoR history of star formation, bubble size, and ionization state. Additionally, TIME-Pilot will produce high signal-to-noise measurements of CO clustering fluctuations, which trace the role of molecular gas in star-forming galaxies at redshifts 0 < z < 2. With its unique atmospheric noise mitigation, TIME-Pilot also significantly improves sensitivity for measuring the kinetic Sunyaev-Zel'dovich (kSZ) effect in galaxy clusters. TIME-Pilot will employ a linear array of spectrometers, each consisting of a parallel-plate diffraction grating. The spectrometer bandwidth covers 185-323 GHz to both probe the entire redshift range of interest and to include channels at the edges of the band for atmospheric noise mitigation. We illuminate the telescope with f/3 horns, which balances the desire to both couple to the sky with the best efficiency per beam, and to pack a large number of horns into the fixed field of view. Feedhorns couple radiation to the waveguide spectrometer gratings. Each spectrometer grating has 190 facets and provides resolving power

  6. Beam experiments towards high-intensity beams in RHIC

    SciTech Connect

    Montag C.; Ahrens, L.; Brennan, J.M.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Hayes, T.; Huang, H.; Mernick, K.; Robert-Demolaize, G.; Smith, K.; Than, R.; Thieberger, P.; Yip, K.; Zeno, K.; Zhang, S.Y.

    2012-05-20

    Proton bunch intensities in RHIC are planned to be increased from 2 {center_dot} 10{sup 11} to 3 {center_dot} 10{sup 11} protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results are presented.

  7. An Introduction to Optical Stellar Interferometry

    NASA Astrophysics Data System (ADS)

    Labeyrie, A.; Lipson, S. G.; Nisenson, P.

    2006-06-01

    1. Introduction; 2 Basic concepts: a qualitative introduction; 3. Interference, diffraction and coherence; 4. Aperture synthesis; 5. Optical effects of the atmosphere; 6. Single-aperture techniques; 7. Intensity interferometry; 8. Amplitude interferometry: techniques and instruments; 9. The hypertelescope; 10. Nulling and coronagraphy; 11. A sampling of interferometric science; 12. Future ground and space projects; Appendices.

  8. An Introduction to Optical Stellar Interferometry

    NASA Astrophysics Data System (ADS)

    Labeyrie, A.; Lipson, S. G.; Nisenson, P.

    2014-03-01

    1. Introduction; 2 Basic concepts: a qualitative introduction; 3. Interference, diffraction and coherence; 4. Aperture synthesis; 5. Optical effects of the atmosphere; 6. Single-aperture techniques; 7. Intensity interferometry; 8. Amplitude interferometry: techniques and instruments; 9. The hypertelescope; 10. Nulling and coronagraphy; 11. A sampling of interferometric science; 12. Future ground and space projects; Appendices.

  9. Optical Interferometry Motivation and History

    NASA Technical Reports Server (NTRS)

    Lawson, Peter

    2006-01-01

    A history and motivation of stellar interferometry is presented. The topics include: 1) On Tides, Organ Pipes, and Soap Bubbles; 2) Armand Hippolyte Fizeau (1819-1896); 3) Fizeau Suggests Stellar Interferometry 1867; 4) Edouard Stephan (1837-1923); 5) Foucault Refractor; 6) Albert A. Michelson (1852-1931); 7) On the Application of Interference Methods to Astronomy (1890); 8) Moons of Jupiter (1891); 9) Other Applications in 19th Century; 10) Timeline of Interferometry to 1938; 11) 30 years goes by; 12) Mount Wilson Observatory; 13) Michelson's 20 ft Interferometer; 14) Was Michelson Influenced by Fizeau? 15) Work Continues in the 1920s and 30s; 16) 50 ft Interferometer (1931-1938); 17) Light Paths in the 50 ft Interferometer; 18) Ground-level at the 50 ft; 19) F.G. Pease (1881-1938); 20) Timeline of Optical Interferometry to 1970; 21) A New Type of Stellar Interferometer (1956); 22) Intensity Interferometer (1963- 1976; 23) Robert Hanbury Brown; 24) Interest in Optical Interferometry in the 1960s; 25) Interferometry in the Early 1970s; and 26) A New Frontier is Opened up in 1974.

  10. Optical Interferometry Motivation and History

    NASA Technical Reports Server (NTRS)

    Lawson, Peter

    2006-01-01

    A history and motivation of stellar interferometry is presented. The topics include: 1) On Tides, Organ Pipes, and Soap Bubbles; 2) Armand Hippolyte Fizeau (1819-1896); 3) Fizeau Suggests Stellar Interferometry 1867; 4) Edouard Stephan (1837-1923); 5) Foucault Refractor; 6) Albert A. Michelson (1852-1931); 7) On the Application of Interference Methods to Astronomy (1890); 8) Moons of Jupiter (1891); 9) Other Applications in 19th Century; 10) Timeline of Interferometry to 1938; 11) 30 years goes by; 12) Mount Wilson Observatory; 13) Michelson's 20 ft Interferometer; 14) Was Michelson Influenced by Fizeau? 15) Work Continues in the 1920s and 30s; 16) 50 ft Interferometer (1931-1938); 17) Light Paths in the 50 ft Interferometer; 18) Ground-level at the 50 ft; 19) F.G. Pease (1881-1938); 20) Timeline of Optical Interferometry to 1970; 21) A New Type of Stellar Interferometer (1956); 22) Intensity Interferometer (1963- 1976; 23) Robert Hanbury Brown; 24) Interest in Optical Interferometry in the 1960s; 25) Interferometry in the Early 1970s; and 26) A New Frontier is Opened up in 1974.

  11. Meson interferometry in relativistic heavy ion collisions

    SciTech Connect

    Not Available

    1993-05-01

    This report contains discussions on the following topics: Recent HBT results form CERN experiment NA44; interferometry results from E802/E859/E866; recent results on two particle correlations from E814; source sizes from CERN data; intermittency and interferometry; Bose-Einstein correlations in 200A GeV S+Au collisions; HBT correlations at STAR; HBT interferometry with PHENIX; HBT calculations from ARC; three pion correlations; and pion correlations in proton-induced reactions.

  12. Optical interferometry diagnostics in laser-driven equation of state experiments

    SciTech Connect

    Cauble, R C; Celliers, P M; Collins, G W; Da Silva, L B; Gold, D M; Kalantar, D H; Remington, B A; Weber, S V

    1999-06-18

    We have developed and tested several optical interferometric diagnostics to measure preheat and shock velocity in high-pressure equation of state experiments on the Nova laser. Theory and practical application of interferometric measurement techniques with illustrative experimental results are presented.

  13. Intensity and memory characteristics of near-death experiences.

    PubMed

    Martial, Charlotte; Charland-Verville, Vanessa; Cassol, Héléna; Didone, Vincent; Van Der Linden, Martial; Laureys, Steven

    2017-07-08

    Memories of Near-Death Experiences (NDEs) seem to be very detailed and stable over time. At present, there is still no satisfactory explanation for the NDEs' rich phenomenology. Here we compared phenomenological characteristics of NDE memories with the reported experience's intensity. We included 152 individuals with a self-reported "classical" NDE (i.e. occurring in life-threatening conditions). All participants completed a mailed questionnaire that included a measure of phenomenological characteristics of memories (the Memory Characteristics Questionnaire; MCQ) and a measure of NDE's intensity (the Greyson NDE scale). Greyson NDE scale total score was positively correlated with MCQ total score, suggesting that participants who described more intense NDEs also reported more phenomenological memory characteristics of NDE. Using MCQ items, our study also showed that NDE's intensity is associated in particular with sensory details, personal importance and reactivation frequency variables. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Patients' dreams and unreal experiences following intensive care unit admission.

    PubMed

    Roberts, Brigit; Chaboyer, Wendy

    2004-01-01

    Dreams and unreal experiences occur commonly in critically ill patients admitted to intensive care unit. This study describes 31 patients' dreams and explores the relationship between patients' subjective recall 12-18 months after intensive care unit discharge and their observed behaviour during their intensive care unit stay. Semi-structured interviews revealed that 74% of longer-term ICU patients (> or = 3 days) reported dreaming, with the majority also describing frightening hallucinations. Only two patients reported long-term negative psychological sequelae, but the short-term consequence of hallucinations may also have an undiscovered impact on patients' recovery.

  15. How we remember the emotional intensity of past musical experiences.

    PubMed

    Schäfer, Thomas; Zimmermann, Doreen; Sedlmeier, Peter

    2014-01-01

    Listening to music usually elicits emotions that can vary considerably in their intensity over the course of listening. Yet, after listening to a piece of music, people are easily able to evaluate the music's overall emotional intensity. There are two different hypotheses about how affective experiences are temporally processed and integrated: (1) all moments' intensities are integrated, resulting in an averaged value; (2) the overall evaluation is built from specific single moments, such as the moments of highest emotional intensity (peaks), the end, or a combination of these. Here we investigated what listeners do when building an overall evaluation of a musical experience. Participants listened to unknown songs and provided moment-to-moment ratings of experienced intensity of emotions. Subsequently, they evaluated the overall emotional intensity of each song. Results indicate that participants' evaluations were predominantly influenced by their average impression but that, in addition, the peaks and end emotional intensities contributed substantially. These results indicate that both types of processes play a role: All moments are integrated into an averaged value but single moments might be assigned a higher value in the calculation of this average.

  16. How we remember the emotional intensity of past musical experiences

    PubMed Central

    Schäfer, Thomas; Zimmermann, Doreen; Sedlmeier, Peter

    2014-01-01

    Listening to music usually elicits emotions that can vary considerably in their intensity over the course of listening. Yet, after listening to a piece of music, people are easily able to evaluate the music's overall emotional intensity. There are two different hypotheses about how affective experiences are temporally processed and integrated: (1) all moments' intensities are integrated, resulting in an averaged value; (2) the overall evaluation is built from specific single moments, such as the moments of highest emotional intensity (peaks), the end, or a combination of these. Here we investigated what listeners do when building an overall evaluation of a musical experience. Participants listened to unknown songs and provided moment-to-moment ratings of experienced intensity of emotions. Subsequently, they evaluated the overall emotional intensity of each song. Results indicate that participants' evaluations were predominantly influenced by their average impression but that, in addition, the peaks and end emotional intensities contributed substantially. These results indicate that both types of processes play a role: All moments are integrated into an averaged value but single moments might be assigned a higher value in the calculation of this average. PMID:25177311

  17. Particle manipulation techniques in AEgIS. Antimatter experiment: gravity, interferometry, spectroscopy

    NASA Astrophysics Data System (ADS)

    Canali, C.; Carraro, C.; Di Noto, L.; Krasnicky, D.; Lagomarsino, V.; Testera, G.; Zavatarelli, S.

    2011-07-01

    The AEgIS experiment ( http://aegis.web.cern.ch ) will measure the gravitational acceleration g of antihydrogen. Once performed this could be the first direct test of the gravitational interaction between matter and antimatter. In the AEgIS experiment a beam of antihydrogen will travel horizontally along a path of about 1 m trough a moiré deflectometer followed by a position sensitive detector. The g value will be obtained measuring the vertical displacement of the annihilation patterns. Before producing the beam, several tasks have to be performed mainly involving positron and electron plasma manipulation and particles cooling in Malmberg-Penning traps. The AEgIS experiment is currently under construction at CERN, meanwhile several tests involving particle manipulation and particle cooling are in progress. In this report some experimental results involving diocotron manipulation of plasma will be presented.

  18. Measurement of group velocity dispersion using white light interferometry: A teaching laboratory experiment

    NASA Astrophysics Data System (ADS)

    Cormack, I. G.; Baumann, F.; Reid, D. T.

    2000-12-01

    A teaching laboratory experiment is described which uses a basic Michelson interferometer arrangement to make fast and accurate measurements of the group velocity dispersion of an optical material using a method based on recording white-light fringes. We present a brief analysis of the theory behind the technique and describe two example measurements, one of the material dispersion of a KTP crystal and another of the reflectivity dispersion of a silver-coated mirror. Details are also given of our implementation of the data analysis using the MATLAB programming environment

  19. Design of experiment for earth rotation and baseline parameter determination from very long baseline interferometry

    NASA Technical Reports Server (NTRS)

    Dermanis, A.

    1977-01-01

    The possibility of recovering earth rotation and network geometry (baseline) parameters are emphasized. The numerical simulated experiments performed are set up in an environment where station coordinates vary with respect to inertial space according to a simulated earth rotation model similar to the actual but unknown rotation of the earth. The basic technique of VLBI and its mathematical model are presented. The parametrization of earth rotation chosen is described and the resulting model is linearized. A simple analysis of the geometry of the observations leads to some useful hints on achieving maximum sensitivity of the observations with respect to the parameters considered. The basic philosophy for the simulation of data and their analysis through standard least squares adjustment techniques is presented. A number of characteristic network designs based on present and candidate station locations are chosen. The results of the simulations for each design are presented together with a summary of the conclusions.

  20. Precision geodesy via radio interferometry.

    NASA Technical Reports Server (NTRS)

    Hinteregger, H. F.; Shapiro, I. I.; Robertson, D. S.; Knight, C. A.; Ergas, R. A.; Whitney, A. R.; Burke, B. F.; Rogers, A. E. E.; Moran, J. M.; Clark, T. A.

    1972-01-01

    Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources and allowed the hydrogen maser clocks at the two sites to be synchronized.

  1. Far infrared tangential interferometry/polarimetry on the National Spherical Tokamak Experiment

    NASA Astrophysics Data System (ADS)

    Park, H. K.; Domier, C. W.; Geck, W. R.; Luhmann, N. C.

    1999-01-01

    Measurement of the core BT(r,t) value is essential in the National Spherical Tokamak Experiment (NSTX), since the effects of paramagnetism and diamagnetism in the NSTX are expected to be considerably greater than that in higher aspect ratio tokamaks. Therefore, without independent BT(r,t) measurement, plasma parameters dependent upon BT such as the q profile and local β value cannot be evaluated. Tangential interferometer/polarimeter systems (eight channels) [H. Park, L. Guttadora, C. Domier, W. R. Geck, and N. C. Luhman, Jr., First and Second NSTX Research Forums, Princeton, NJ, 1997 (unpublished)] for the NSTX will provide temporally and radially resolved toroidal field profile [BT(r,t)] and two-dimensional electron density profile [ne(r,t)] data. The outcome of the proposed system is extremely important to the study of confinement, heating, and stability of the NSTX plasmas. The research task is largely based on utilizing existing hardware from the TFTR multichannel infrared interferometer system [D. K. Mansfield, H. K. Park, L. C. Johnson, H. Anderson, S. Foote, B. Clifton, and C. H. Ma, Appl. Opt. 26, 4469 (1987) and H. K. Park, D. K. Mansfield, and C. L. Johnson, Proceedings of the 3rd International Symposium on Laser-Aided Plasma Diagnostic, Los Angeles, CA, 28-30 Oct. 1987 (unpublished), pp. 96-104] which will be reconfigured into a tangential system for NSTX, and to develop the additional hardware required to complete the system.

  2. Intense Muon Beams for Experiments at Project X

    SciTech Connect

    C.M. Ankenbrandt, R.P. Johnson, C. Y. Yoshikawa, V.S. Kashikhin, D.V. Neuffer, J. Miller, R.A. Rimmer

    2011-03-01

    A coherent approach for providing muon beams to several experiments for the intensity-frontier program at Project X is described. Concepts developed for the front end of a muon collider/neutrino factory facility, such as phase rotation and ionization cooling, are applied, but with significant differences. High-intensity experiments typically require high-duty-factor beams pulsed at a time interval commensurate with the muon lifetime. It is challenging to provide large RF voltages at high duty factor, especially in the presence of intense radiation and strong magnetic fields, which may preclude the use of superconducting RF cavities. As an alternative, cavities made of materials such as ultra-pure Al and Be, which become very good –but not super– conductors at cryogenic temperatures, can be used.

  3. Previous birth experience in women with intense fear of childbirth.

    PubMed

    Nilsson, Christina; Bondas, Terese; Lundgren, Ingela

    2010-01-01

    To describe the meaning of previous experiences of childbirth in pregnant women who have exhibited intense fear of childbirth such that it has an impact on their daily lives. A descriptive phenomenological study. A maternity clinic for women with fear of childbirth in the western part of Sweden. Nine women with intense fear of childbirth who were pregnant with their second child and considered their previous birth experiences negative. Interviews that were transcribed verbatim and analyzed with a reflective life-world approach. The essential meanings that emerged were a sense of not being present in the delivery room and an incomplete childbirth experience. The women felt as if they had no place there, that they were unable to take their place, and that even if the midwife was present, she did not provide support. The experience remained etched in the women's minds and gave rise to feelings of fear, loneliness, and lack of faith in their ability to give birth and diminished trust in maternity care. These experiences contrasted with brief moments that made sense. Previous childbirth experiences for pregnant women with intense fear of childbirth have a deep influence and can be related to suffering and birth trauma. The implication is to provide maternity care where the nurse/midwife is present and supports women during birth in a way that enables them to be present and take their place during birth.

  4. An Intensive Cultural Experience in a Rural Area.

    ERIC Educational Resources Information Center

    Thomas, Mary Durand; Olivares, Sergio A.; Kim, Hyun Jung; Beilke, Cheryle

    2003-01-01

    Discusses how, following an intensive 2-day clinical experience for nursing students in a rural, culturally diverse region, student evaluations and papers showed evidence of cultural learning and increased knowledge of rural health care systems. Includes reflections by a teaching associate and two students. (Contains 33 references.) (SK)

  5. Lessons learned from past experience with intensive livestock management systems.

    PubMed

    Cronin, G M; Rault, J L; Glatz, P C

    2014-04-01

    The main impetus for 'modern' intensive animal production occurred after the Second World War, when Western governments developed policies to increase the availability of cheap, safe food for their populations. Livestock benefit under intensive husbandry by protection from environmental extremes and predators, and better nutritional and health management. Nevertheless, there are costs to the animal, such as impaired social behaviour, limited choice of living environment or pen mates, poor environmental stimulation and behavioural restrictions. The rapid progress in genetic selection of production traits has also, in some cases, adversely affected welfare by creating anatomical and metabolic problems. Above all, the intensively housed animal is heavily reliant on the stockperson and, therefore, inadequate care and husbandry practices by the stockperson may be the largest welfare risk. In a future in which the food supply may be limited as the world's population grows and land availability shrinks, intensive animal production is likely to expand. At the same time, ethical considerations surrounding intensive farming practices may also become more prominent. Novel technologies provide the opportunity to enhance both the productivity and welfare of intensively kept animals. Developing countries are also establishing more intensive commercial systems to meet their growing need for animal protein. Intensive livestock production in such countries has the potential for major expansion, particularly if such developments address the key constraints of poor welfare, inadequate nutrition, poor reproduction, poor housing, and high mortality often seen with traditional systems, and if farmer access to emerging market opportunities is improved. However, as shown by previous experience, inadequate regulation and staff who lack the appropriate training to care for the welfare of intensively housed livestock can be major challenges to overcome.

  6. Compression of intensity interferometry signals

    NASA Astrophysics Data System (ADS)

    Ribak, Erez N.; Shulamy, Yaron

    2016-02-01

    Correlations between photon currents from separate light-collectors provide information on the shape of the source. When the light-collectors are well separated, for example in space, transmission of these currents to a central correlator is limited by band-width. We study the possibility of compression of the photon fluxes and find that traditional compression methods have a similar chance of achieving this goal compared to compressed sensing.

  7. Staff empowerment in intensive care: nurses' and physicians' lived experiences.

    PubMed

    Wåhlin, Ingrid; Ek, Anna-Christina; Idvall, Ewa

    2010-10-01

    The purpose of the study was to describe empowerment from the perspective of intensive care staff. What makes intensive care staff experience inner strength and power? Intensive care staff are repeatedly exposed to traumatic situations and demanding events, which could result in stress and burnout symptoms. A higher level of psychological empowerment at the workplace is associated with increased work satisfaction and mental health, fewer burnout symptoms and a decreased number of sick leave days. Open-ended interviews were conducted with 12 intensive care unit (ICU) staff (four registered nurses, four enrolled nurses and four physicians) in southern Sweden. Data were analysed using a phenomenological method. Intensive care staff were found to be empowered both by internal processes such as feelings of doing good, increased self-esteem/self-confidence and increased knowledge and skills, and by external processes such as nourishing meetings, well functioning teamwork and a good atmosphere. Findings show that not only personal knowledge and skills, but also a supporting atmosphere and a good teamwork, has to be focused and encouraged by supervisors in order to increase staff's experiences of empowerment. Staff also need a chance to feel that they do something good for patients, next of kin and other staff members. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Estimating storm areal average rainfall intensity in field experiments

    NASA Astrophysics Data System (ADS)

    Peters-Lidard, Christa D.; Wood, Eric F.

    1994-07-01

    Estimates of areal mean precipitation intensity derived from rain gages are commonly used to assess the performance of rainfall radars and satellite rainfall retrieval algorithms. Areal mean precipitation time series collected during short-duration climate field studies are also used as inputs to water and energy balance models which simulate land-atmosphere interactions during the experiments. In two recent field experiments (1987 First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) and the Multisensor Airborne Campaign for Hydrology 1990 (MAC-HYDRO '90)) designed to investigate the climatic signatures of land-surface forcings and to test airborne sensors, rain gages were placed over the watersheds of interest. These gages provide the sole means for estimating storm precipitation over these areas, and the gage densities present during these experiments indicate that there is a large uncertainty in estimating areal mean precipitation intensity for single storm events. Using a theoretical model of time- and area-averaged space- time rainfall and a model rainfall generator, the error structure of areal mean precipitation intensity is studied for storms statistically similar to those observed in the FIFE and MAC-HYDRO field experiments. Comparisons of the error versus gage density trade-off curves to those calculated using the storm observations show that the rainfall simulator can provide good estimates of the expected measurement error given only the expected intensity, coefficient of variation, and rain cell diameter or correlation length scale, and that these errors can quickly become very large (in excess of 20%) for certain storms measured with a network whose size is below a "critical" gage density. Because the mean storm rainfall error is particularly sensitive to the correlation length, it is important that future field experiments include radar and/or dense rain gage networks capable of accurately characterizing the

  9. Special topics in infrared interferometry

    NASA Astrophysics Data System (ADS)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  10. Atom Interferometry

    ScienceCinema

    Mark Kasevich

    2016-07-12

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  11. Atom Interferometry

    SciTech Connect

    Mark Kasevich

    2008-05-07

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  12. Atom Interferometry

    SciTech Connect

    Kasevich, Mark

    2008-05-08

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton's constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gyroscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be used to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  13. More intense experiences, less intense forecasts: why people overweight probability specifications in affective forecasts.

    PubMed

    Buechel, Eva C; Zhang, Jiao; Morewedge, Carey K; Vosgerau, Joachim

    2014-01-01

    We propose that affective forecasters overestimate the extent to which experienced hedonic responses to an outcome are influenced by the probability of its occurrence. The experience of an outcome (e.g., winning a gamble) is typically more affectively intense than the simulation of that outcome (e.g., imagining winning a gamble) upon which the affective forecast for it is based. We suggest that, as a result, experiencers allocate a larger share of their attention toward the outcome (e.g., winning the gamble) and less to its probability specifications than do affective forecasters. Consequently, hedonic responses to an outcome are less sensitive to its probability specifications than are affective forecasts for that outcome. The results of 6 experiments provide support for our theory. Affective forecasters overestimated how sensitive experiencers would be to the probability of positive and negative outcomes (Experiments 1 and 2). Consistent with our attentional account, differences in sensitivity to probability specifications disappeared when the attention of forecasters was diverted from probability specifications (Experiment 3) or when the attention of experiencers was drawn toward probability specifications (Experiment 4). Finally, differences in sensitivity to probability specifications between forecasters and experiencers were diminished when the forecasted outcome was more affectively intense (Experiments 5 and 6).

  14. More Intense Experiences, Less Intense Forecasts: Why People Overweight Probability Specifications in Affective Forecasts

    PubMed Central

    Buechel, Eva C.; Zhang, Jiao; Morewedge, Carey K.; Vosgerau, Joachim

    2014-01-01

    We propose that affective forecasters overestimate the extent to which experienced hedonic responses to an outcome are influenced by the probability of its occurrence. The experience of an outcome (e.g., winning a gamble) is typically more affectively intense than the simulation of that outcome (e.g., imagining winning a gamble) upon which the affective forecast for it is based. We suggest that, as a result, experiencers allocate a larger share of their attention toward the outcome (e.g., winning the gamble) and less to its probability specifications than do affective forecasters. Consequently, hedonic responses to an outcome are less sensitive to its probability specifications than are affective forecasts for that outcome. The results of 6 experiments provide support for our theory. Affective forecasters overestimated how sensitive experiencers would be to the probability of positive and negative outcomes (Experiments 1 and 2). Consistent with our attentional account, differences in sensitivity to probability specifications disappeared when the attention of forecasters was diverted from probability specifications (Experiment 3) or when the attention of experiencers was drawn toward probability specifications (Experiment 4). Finally, differences in sensitivity to probability specifications between forecasters and experiencers were diminished when the forecasted outcome was more affectively intense (Experiments 5 and 6). PMID:24128184

  15. Perceiving bodies in motion: expression intensity, empathy, and experience.

    PubMed

    Sevdalis, Vassilis; Keller, Peter E

    2012-10-01

    This study investigated the perceptual identification of individuals' intended expression intensity in point-light displays depicting dance. Participants watched point-light displays of 200-1,000-ms duration, as well as static displays, of expressive and inexpressive dance performances. The task was to identify the intended expression intensity of the performer. The results indicate that expression intensity could be discerned reliably only from dynamic displays, even when they were as short as 200 ms, though the accuracy of judgments increased with exposure duration. Judgment accuracy for dynamic displays was positively correlated with self-report empathy indices and confidence in judgments. Accuracy for these displays also correlated with indices of informal music and dance experience. The findings are discussed in relation to sensorimotor and cognitive-emotional processes underlying action understanding and social cognition.

  16. An in situ method for diagnosing phase shifting interferometry

    NASA Astrophysics Data System (ADS)

    Shao, J.; Ma, D.; Zhang, H.; Xie, Y.

    2016-05-01

    Current diagnosing phase shifting interferometry is a time and funds consuming process. Hence a brief and effective method is necessary to satisfy the real-time testing. In this paper, mathematical solutions for errors were deduced from the difference of intensity patterns. Based on the diversity of error distributions, an effective method for distinguishing and diagnosing the error sources is proposed and verified by an elaborative designed simulation. In the actual comparison experiment, vibration, phase-shift error and intensity fluctuation were imposed to demonstrate this method. The results showed that this method can be applied into the real-time measurement and provide an in situ diagnosing technique.

  17. A circuit processing method for restraining DC drift for Interferometry of micro vibration measurement

    NASA Astrophysics Data System (ADS)

    Hou, Hao; Wang, Xuanze; Zhai, Zhongsheng

    2016-01-01

    A circuit processing method is present to restrain DC drift after analyzing the traditional signal processing method of interferometry for micro vibration measurement. At first, the circuit diagram is designed and its mathematical model is built, then the theoretical equations of the output signal are derived with the practical parameters. By using SIMULINK simulation, the process for restraining DC drift is present on the conditions of the variations of background intensity. The validity of feedback circuit was verified through analyzing the real experiment data. Theoretical predictions match simulation results, showing that this method effectively restrains DC drift for interferometry of micro vibration measurement and it greatly improves the system's stability.

  18. Quantum Interferometry

    NASA Technical Reports Server (NTRS)

    Dowling, Jonathan P.

    2000-01-01

    Recently, several researchers, including yours truly, have been able to demonstrate theoretically that quantum photon entanglement has the potential to also revolutionize the entire field of optical interferometry, by providing many orders of magnitude improvement in interferometer sensitivity. The quantum entangled photon interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like 1/Sqrt[N], where N is the number of particles (photons, electrons, atoms, neutrons) passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of Sqrt[N] (square root of N) to scale like 1/N, which is the limit imposed by the Heisenberg Uncertainty Principle. For optical (laser) interferometers operating at milliwatts of optical power, this quantum sensitivity boost corresponds to an eight-order-of-magnitude improvement of signal to noise. Applications are to tests of General Relativity such as ground and orbiting optical interferometers for gravity wave detection, Laser Interferometer Gravity Observatory (LIGO) and the European Laser Interferometer Space Antenna (LISA), respectively.

  19. Quantum Interferometry

    NASA Technical Reports Server (NTRS)

    Dowling, Jonathan P.

    2000-01-01

    Recently, several researchers, including yours truly, have been able to demonstrate theoretically that quantum photon entanglement has the potential to also revolutionize the entire field of optical interferometry, by providing many orders of magnitude improvement in interferometer sensitivity. The quantum entangled photon interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like 1/Sqrt[N], where N is the number of particles (photons, electrons, atoms, neutrons) passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of Sqrt[N] (square root of N) to scale like 1/N, which is the limit imposed by the Heisenberg Uncertainty Principle. For optical (laser) interferometers operating at milliwatts of optical power, this quantum sensitivity boost corresponds to an eight-order-of-magnitude improvement of signal to noise. Applications are to tests of General Relativity such as ground and orbiting optical interferometers for gravity wave detection, Laser Interferometer Gravity Observatory (LIGO) and the European Laser Interferometer Space Antenna (LISA), respectively.

  20. Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

    PubMed Central

    Baryshev, Sergey V.; Erck, Robert A.; Moore, Jerry F.; Zinovev, Alexander V.; Tripa, C. Emil; Veryovkin, Igor V.

    2013-01-01

    In materials science and engineering it is often necessary to obtain quantitative measurements of surface topography with micrometer lateral resolution. From the measured surface, 3D topographic maps can be subsequently analyzed using a variety of software packages to extract the information that is needed. In this article we describe how white light interferometry, and optical profilometry (OP) in general, combined with generic surface analysis software, can be used for materials science and engineering tasks. In this article, a number of applications of white light interferometry for investigation of surface modifications in mass spectrometry, and wear phenomena in tribology and lubrication are demonstrated. We characterize the products of the interaction of semiconductors and metals with energetic ions (sputtering), and laser irradiation (ablation), as well as ex situ measurements of wear of tribological test specimens. Specifically, we will discuss: Aspects of traditional ion sputtering-based mass spectrometry such as sputtering rates/yields measurements on Si and Cu and subsequent time-to-depth conversion. Results of quantitative characterization of the interaction of femtosecond laser irradiation with a semiconductor surface. These results are important for applications such as ablation mass spectrometry, where the quantities of evaporated material can be studied and controlled via pulse duration and energy per pulse. Thus, by determining the crater geometry one can define depth and lateral resolution versus experimental setup conditions. Measurements of surface roughness parameters in two dimensions, and quantitative measurements of the surface wear that occur as a result of friction and wear tests. Some inherent drawbacks, possible artifacts, and uncertainty assessments of the white light interferometry approach will be discussed and explained. PMID:23486006

  1. Characterization of surface modifications by white light interferometry: applications in ion sputtering, laser ablation, and tribology experiments.

    PubMed

    Baryshev, Sergey V; Erck, Robert A; Moore, Jerry F; Zinovev, Alexander V; Tripa, C Emil; Veryovkin, Igor V

    2013-02-27

    In materials science and engineering it is often necessary to obtain quantitative measurements of surface topography with micrometer lateral resolution. From the measured surface, 3D topographic maps can be subsequently analyzed using a variety of software packages to extract the information that is needed. In this article we describe how white light interferometry, and optical profilometry (OP) in general, combined with generic surface analysis software, can be used for materials science and engineering tasks. In this article, a number of applications of white light interferometry for investigation of surface modifications in mass spectrometry, and wear phenomena in tribology and lubrication are demonstrated. We characterize the products of the interaction of semiconductors and metals with energetic ions (sputtering), and laser irradiation (ablation), as well as ex situ measurements of wear of tribological test specimens. Specifically, we will discuss: i. Aspects of traditional ion sputtering-based mass spectrometry such as sputtering rates/yields measurements on Si and Cu and subsequent time-to-depth conversion. ii. Results of quantitative characterization of the interaction of femtosecond laser irradiation with a semiconductor surface. These results are important for applications such as ablation mass spectrometry, where the quantities of evaporated material can be studied and controlled via pulse duration and energy per pulse. Thus, by determining the crater geometry one can define depth and lateral resolution versus experimental setup conditions. iii. Measurements of surface roughness parameters in two dimensions, and quantitative measurements of the surface wear that occur as a result of friction and wear tests. Some inherent drawbacks, possible artifacts, and uncertainty assessments of the white light interferometry approach will be discussed and explained.

  2. A Review of Astrophysics Experiments on Intense Lasers

    SciTech Connect

    Remington, B.A.; Arnett, D.; Drake, R.P.; Takabe, H.

    1999-03-03

    Astrophysics traditionally has been the domain of large astronomical observatories and theorists' computers, the former producing images from deep space, and the latter constructing intricate models to explain the observations. A component often missing has been the ability to quantitatively test the theories and models in an experimental setting where the initial and final states are well characterized. In a new development, intense lasers are being used to recreate aspects of astrophysical phenomena in the laboratory, allowing the creation of experimental testbeds where theory and modeling can be quantitatively compared with data. We summarize here several areas of astrophysics: supernovae, supernova remnants, gamma-ray bursts, and giant planets. In each of these areas, experiments are under development at intense laser facilities to test and refine our understanding of these phenomena.

  3. High intensity positron beam and angular correlation experiments at Livermore

    SciTech Connect

    Howell, R.H.; Rosenberg, I.J.; Meyer, P.; Fluss, M.J.

    1985-03-01

    A positron beam apparatus that produces a variable energy positron beam with sufficient intensity to perform new positron experiments in an ultrahigh vacuum environment has been installed at the Lawrence Livermore 100 MeV electron linac. We have installed two large area position sensitive gamma-ray detectors to measure angular correlations in two dimensions and a separate highly collimated detector to measure positronium energy distributions by time-of-flight velocity determination. Data from measurements on single crystals of Cu will be described.

  4. Family members' experiences of the intensive care unit waiting room.

    PubMed

    Kutash, Mary; Northrop, Linda

    2007-11-01

    This paper is a report of a study to explore family members' perspectives and experiences of waiting rooms in adult intensive care units. Waiting to visit family members who are hospitalized in intensive care units can be very stressful. Although flexible and or open visiting is practised in many hospitals, family members may spend a great deal of time in the waiting room. A qualitative design using semi-structured interviews was used and the data were collected in 2004. A convenience sample of six visitors was recruited from waiting rooms of three different adult intensive care units. Data collection and analysis were concurrent. Six categories emerged from the data that included structural and subjective aspects of waiting: 'close proximity' referred to the importance of a close physical distance to their family member; 'caring staff' captured the comfort family members felt when staff showed caring behaviours towards relative; 'need for a comfortable environment' represented the impact of the design of the waiting room on family members well-being; 'emotional support' referred to the waiting room as a place where comfort was found by sharing with others; 'rollercoaster of emotions' captured the range of emotions experienced by family members; 'information' referred to the importance of receiving information about their relative. Future research should focus on the impact of the interior design of waiting rooms on the comfort and welfare of family members and on identifying needs of family members across different cultures.

  5. Expressing death risk as condensed life experience and death intensity.

    PubMed

    Ioannidis, John P A

    2013-08-01

    Some risk exposures, including many medical and surgical procedures, typically carry hazards of death that are difficult to convey and appreciate in absolute terms. I propose presenting the death risk as a condensed life experience (i.e., the equivalent amount of life T that would carry the same cumulative mortality hazard for a person of the same age and sex based on life tables). For example, if the risk of death during an elective 1-hour procedure is 0.01%, and same-age and same-sex people have a 0.01% death risk over 1 month, one can inform the patient that "this procedure carries the same death risk as living 1 month of normal life." Comparative standards from other risky activities or from a person with the same disease at the same stage and same predictive profile could also be used. A complementary metric that may be useful to consider is the death intensity. The death intensity λ is the hazard function that shows the fold-risk estimate of dying compared with the reference person. The death intensity can vary substantially for different phases of the event, operation, or procedure (e.g., intraoperative, early postoperative, late postoperative), and this variability may also be useful to convey. T will vary depending on the time window for which it is computed. I present examples for calculating T and λ using literature data on accidents, ascent to Mount Everest, and medical and surgical procedures.

  6. Accurate phase-shifting digital interferometry.

    PubMed

    Atlan, M; Gross, M; Absil, E

    2007-06-01

    In phase-shifting interferometry experiments, the accuracy of the phase shift is a major issue. Many experimental and data analyses are done to cancel phase-shift errors inherent to the modulation techniques used. We propose to remove most of the phase-shift error by recourse to a frequency-shifting method. This approach can be applied to both holography and interferometry. We validate the idea with a holographic experiment.

  7. Nonlocal Pancharatnam phase in two-photon interferometry

    SciTech Connect

    Mehta, Poonam; Samuel, Joseph; Sinha, Supurna

    2010-09-15

    We propose a polarized intensity interferometry experiment, which measures the nonlocal Pancharatnam phase acquired by a pair of Hanbury-Brown-Twiss photons. The setup involves two polarized thermal sources illuminating two polarized detectors. Varying the relative polarization angle of the detectors introduces a two-photon geometric phase. Local measurements at either detector do not reveal the effects of the phase, which is an optical analog of the multiparticle Aharonov-Bohm effect. The geometric phase sheds light on the three-slit experiment and suggests ways of tuning entanglement.

  8. Patients' experiences of technology and care in adult intensive care.

    PubMed

    Stayt, Louise Caroline; Seers, Kate; Tutton, Elizabeth

    2015-09-01

    To investigate patients' experiences of technology in an adult intensive care unit. Technology is fundamental to support physical recovery from critical illness in Intensive Care Units. As well as physical corollaries, psychological disturbances are reported in critically ill patients at all stages of their illness and recovery. Nurses play a key role in the physical and psychological care of patients;, however, there is a suggestion in the literature that the presence of technology may dehumanise patient care and distract the nurse from attending to patients psychosocial needs. Little attention has been paid to patients' perceptions of receiving care in a technological environment. This study was informed by Heideggerian phenomenology. The research took place in 2009-2011 in a university hospital in England. Nineteen participants who had been patients in ICU were interviewed guided by an interview topic prompt list. Interviews were transcribed verbatim and analysed using Van Manen's framework. Participants described technology and care as inseparable and presented their experiences as a unified encounter. The theme 'Getting on with it' described how participants endured technology by 'Being Good' and 'Being Invisible'. 'Getting over it' described why participants endured technology by 'Bowing to Authority' and viewing invasive technologies as a 'Necessary Evil'. Patients experienced technology and care as a series of paradoxical relationships: alienating yet reassuring, uncomfortable yet comforting, impersonal yet personal. By maintaining a close and supportive presence and providing personal comfort and care nurses may minimize the invasive and isolating potential of technology. © 2015 John Wiley & Sons Ltd.

  9. Analysis of the feasibility of an experiment to measure carbon monoxide in the atmosphere. [using remote platform interferometry

    NASA Technical Reports Server (NTRS)

    Bortner, M. H.; Alyea, F. N.; Grenda, R. N.; Liebling, G. R.; Levy, G. M.

    1973-01-01

    The feasibility of measuring atmospheric carbon monoxide from a remote platform using the correlation interferometry technique was considered. It has been determined that CO data can be obtained with an accuracy of 10 percent using this technique on the first overtone band of CO at 2.3 mu. That band has been found to be much more suitable than the stronger fundamental band at 4.6 mu. Calculations for both wavelengths are presented which illustrate the effects of atmospheric temperature profiles, inversion layers, ground temperature and emissivity, CO profile, reflectivity, and atmospheric pressure. The applicable radiative transfer theory on which these calculations are based is described together with the principles of the technique.

  10. Precision Selenodesy via Differential Very-Long-Baseline Interferometry. Ph.D. Thesis; [Apollo lunar surface experiments package

    NASA Technical Reports Server (NTRS)

    King, R. W., Jr.

    1975-01-01

    The technique of differential very-long baseline interferometry was used to measure the relative positions of the ALSEP transmitters at the Apollo 12, 14, 15, 16, and 17 lunar landing sites with uncertainties less than 0.005 of geocentric arc. These measurements yielded improved determinations of the selenodetic coordinates of the Apollo landing sites, and of the physical libration of the moon. By means of a new device, the differential Doppler receiver (DDR), instrumental errors were reduced to less than the equivalent of 0.001. DDRs were installed in six stations of the NASA spaceflight tracking and data network and used in an extensive program of observations beginning in March 1973.

  11. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2010-03-16

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  12. Family experience survey in the surgical intensive care unit.

    PubMed

    Twohig, Bridget; Manasia, Anthony; Bassily-Marcus, Adel; Oropello, John; Gayton, Matthew; Gaffney, Christine; Kohli-Seth, Roopa

    2015-11-01

    The experience of critical care is stressful for both patients and their families. This is especially true when patients are not able to make their own care decisions. This article details the creation of a Family Experience Survey in a surgical intensive care unit (SICU) to capture and improve overall experience. Kolcaba's "Enhanced Comfort Theory" provided the theoretical basis for question formation, specifically in regards to the four aspects of comfort: "physical," "psycho-spiritual," "sociocultural" and "environmental." Survey results were analyzed in real-time to identify and implement interventions needed for issues raised. Overall, there was a high level of satisfaction reported especially with quality of care provided to patients, communication and availability of nurses and doctors, explanations from staff, inclusion in decision making, the needs of patients being met, quality of care provided to patients and cleanliness of the unit. It was noted that 'N/A' was indicated for cultural needs and spiritual needs, a chaplain now rounds on all patients daily to ensure these services are more consistently offered. In addition, protocols for doctor communication with families, palliative care consults, daily bleach cleaning of high touch areas in patient rooms and nurse-led progressive mobility have been implemented. Enhanced comfort theory enabled the opportunity to identify and provide a more 'broad' approach to care for patients and families. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. A review of astrophysics experiments on intense lasers

    NASA Astrophysics Data System (ADS)

    Remington, B. A.

    1999-11-01

    Modern, high power laser facilities open new possibilities for simulating astrophysical systems in the laboratory.(S.J. Rose, Laser & Part. Beams 9, 869 (1991); B.H. Ripin et al., Laser & Part. Beams 8, 183 (1990); B.A. Remington et al., Science 284, 1488 (1999); H. Takabe et al., Plasma Phys. Contr. Fusion 41, A75 (1999); R.P. Drake, J. Geophys. Res. 104, 14505 (1999).) Scaled investigations of the hydrodynamics.(J. Kane et al., Phys. Plasmas 6, 2065 (1999); R.P. Drake et al., Ap. J. 500, L157 (1998); D. Ryutov et al., Ap. J. 518, 821 (1999).) and radiative transfer.(J. Wark et al., Phys. Plasmas 4, 2004 (1997); P.K. Patel et al., JQSRT 58, 835 (1997).) relevant to supernovae, and opacities relevant to stellar interiors.(F.J. Rogers and C.A. Iglesias, Science 263, 50 (1994); H. Merdji et al., JSQRT 58, 783 (1997).) are now possible with laser experiments. Equations of state relevant to the interiors of giant planets and brown dwarfs are also being experimentally accessed.(G.W. Collins et al., Science 281, 1178 (1998); A. Benuzzi et al., Phys. Rev. E 54, 2162 (1996).) With the construction of the NIF laser in the U.S., and the LIL and LMJ lasers in France, controlled investigations of thermonuclear burn physics will become possible in the next decade. And with existing and future ultra-high intensity short pulse lasers, investigations of relativistic astrophysical plasmas are becoming possible.(M.H. Key et al., Phys. Plasmas 5, 1966 (1998); F. Pegoraro et al., Plasma Phys. Contr. Fus. 39, B261 (1997).) A review of laboratory astrophysics experiments using intense lasers will be presented, and the potential for the future will be discussed.

  14. Precision Geodesy via Radio Interferometry.

    PubMed

    Hinteregger, H F; Shapiro, I I; Robertson, D S; Knight, C A; Ergas, R A; Whitney, A R; Rogers, A E; Moran, J M; Clark, T A; Burke, B F

    1972-10-27

    Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.

  15. Data System Architectures: Recent Experiences from Data Intensive Projects

    NASA Astrophysics Data System (ADS)

    Palanisamy, G.; Frame, M. T.; Boden, T.; Devarakonda, R.; Zolly, L.; Hutchison, V.; Latysh, N.; Krassovski, M.; Killeffer, T.; Hook, L.

    2014-12-01

    U.S. Federal agencies are frequently trying to address new data intensive projects that require next generation of data system architectures. This presentation will focus on two new such architectures: USGS's Science Data Catalog (SDC) and DOE's Next Generation Ecological Experiments - Arctic Data System. The U.S. Geological Survey (USGS) developed a Science Data Catalog (data.usgs.gov) to include records describing datasets, data collections, and observational or remotely-sensed data. The system was built using service oriented architecture and allows USGS scientists and data providers to create and register their data using either a standards-based metadata creation form or simply to register their already-created metadata records with the USGS SDC Dashboard. This dashboard then compiles the harvested metadata records and sends them to the post processing and indexing service using the JSON format. The post processing service, with the help of various ontologies and other geo-spatial validation services, auto-enhances these harvested metadata records and creates a Lucene index using the Solr enterprise search platform. Ultimately, metadata is made available via the SDC search interface. DOE's Next Generation Ecological Experiments (NGEE) Arctic project deployed a data system that allows scientists to prepare, publish, archive, and distribute data from field collections, lab experiments, sensors, and simulated modal outputs. This architecture includes a metadata registration form, data uploading and sharing tool, a Digital Object Identifier (DOI) tool, a Drupal based content management tool (http://ngee-arctic.ornl.gov), and a data search and access tool based on ORNL's Mercury software (http://mercury.ornl.gov). The team also developed Web-metric tools and a data ingest service to visualize geo-spatial and temporal observations.

  16. Deep frequency modulation interferometry.

    PubMed

    Gerberding, Oliver

    2015-06-01

    Laser interferometry with pm/Hz precision and multi-fringe dynamic range at low frequencies is a core technology to measure the motion of various objects (test masses) in space and ground based experiments for gravitational wave detection and geodesy. Even though available interferometer schemes are well understood, their construction remains complex, often involving, for example, the need to build quasi-monolithic optical benches with dozens of components. In recent years techniques have been investigated that aim to reduce this complexity by combining phase modulation techniques with sophisticated digital readout algorithms. This article presents a new scheme that uses strong laser frequency modulations in combination with the deep phase modulation readout algorithm to construct simpler and easily scalable interferometers.

  17. Fluorescence interferometry: principles and applications in biology.

    PubMed

    Bilenca, Alberto; Cao, Jing; Colice, Max; Ozcan, Aydogan; Bouma, Brett; Raftery, Laurel; Tearney, Guillermo

    2008-01-01

    The use of fluorescence radiation is of fundamental importance for tackling measurement problems in the life sciences, with recent demonstrations of probing biological systems at the nanoscale. Usually, fluorescent light-based tools and techniques use the intensity of light waves, which is easily measured by detectors. However, the phase of a fluorescence wave contains subtle, but no less important, information about the wave; yet, it has been largely unexplored. Here, we introduce the concept of fluorescence interferometry to allow the measurement of phase information of fluorescent light waves. In principle, fluorescence interferometry can be considered a unique form of optical low-coherence interferometry that uses fluorophores as a light source of low temporal coherence. Fluorescence interferometry opens up new avenues for developing new fluorescent light-based imaging, sensing, ranging, and profiling methods that to some extent resemble interferometric techniques based on white light sources. We propose two experimental realizations of fluorescence interferometry that detect the interference pattern cast by the fluorescence fields. This article discusses their measurement capabilities and limitations and compares them with those offered by optical low-coherence interferometric schemes. We also describe applications of fluorescence interferometry to imaging, ranging, and profiling tasks and present experimental evidences of wide-field cross-sectional imaging with high resolution and large range of depth, as well as quantitative profiling with nanometer-level precision. Finally, we point out future research directions in fluorescence interferometry, such as fluorescence tomography of whole organisms and the extension to molecular interferometry by means of quantum dots and bioluminescence.

  18. Polarization Phase-Shift Interferometry: A Simple Laboratory Setup

    NASA Astrophysics Data System (ADS)

    Vannoni, Maurizio; Trivi, Marcelo; Molesini, Giuseppe

    2008-04-01

    An interferometry experiment is proposed, working on a Twyman-Green optical configuration. The interferogram is acquired with a digital camera and processed. Using polarization components the interferogram is phase-shifted and four different interferograms are acquired. The experiment is proposed as an introduction to modern phase-shift interferometry, using concepts and laboratory equipment at the level of undergraduate optics courses.

  19. Soft x-ray interferometry

    SciTech Connect

    Not Available

    1993-09-01

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument`s components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200{angstrom} wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency.

  20. Synthetic Aperture Radar Interferometry

    NASA Technical Reports Server (NTRS)

    Rosen, P. A.; Hensley, S.; Joughin, I. R.; Li, F.; Madsen, S. N.; Rodriguez, E.; Goldstein, R. M.

    1998-01-01

    Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.

  1. Investigating the Mercalli Intensity Scale through "Lived Experience"

    ERIC Educational Resources Information Center

    Jones, Richard

    2012-01-01

    The modified Mercalli (MM) intensity scale is composed of 12 increasing levels of intensity that range from imperceptible shaking to catastrophic destruction and is designated by Roman numerals I through XII. Although qualitative in nature, it can provide a more concrete model for middle and high school students striving to understand the dynamics…

  2. Investigating the Mercalli Intensity Scale through "Lived Experience"

    ERIC Educational Resources Information Center

    Jones, Richard

    2012-01-01

    The modified Mercalli (MM) intensity scale is composed of 12 increasing levels of intensity that range from imperceptible shaking to catastrophic destruction and is designated by Roman numerals I through XII. Although qualitative in nature, it can provide a more concrete model for middle and high school students striving to understand the dynamics…

  3. Intense convection over West Africa during AMMA SOP3 experiment

    NASA Astrophysics Data System (ADS)

    Lenouo, André; Sall, Saïdou Moustapha; Badiane, Daouda; Gaye, Amadou Thierno; Kamga Mkankam, F.

    2016-11-01

    ERA-Interim product from the European Center for Medium-Range Weather Forecast (ECMWF) assimilation of African Monsoon Multidisciplinary Analysis (AMMA) resources, Meteosat satellite images, and synoptic observations were used to study local- and regional-scale environments associated with intense convective systems during the AMMA-SOP3 experiment over West Africa in the Northern Hemisphere of summer 2006. The convective system, from the 21st to 23rd of August 2006, was more active at 0000 and 1800 UTC showing diurnal cycle of deep convection over West Africa where the African easterly waves (AEWs) are developed downstream. Downstream barotropic and baroclinic energy conversions associated with strong AEWs are important for the maintenance of AEW activity in West Africa. Barotropic energy conversions dominate south of the African easterly jet (AEJ), while baroclinic energy conversions are most important north of the AEJ. From a dynamical viewpoint, the low-level vorticity presents strong positive values over the sea and Sahara zone, indicating that exists on the cyclonic shear side of the African easterly jet, which is consistent with baroclinic growth. The 925-hPa equivalent potential temperature structure show a maximum over the Sahara which corresponds to the depression observed in this region. A mosaic of three hourly infrared (IR) satellite images, depicts a very distinct signal from an initial region of convection, developing through several stages and moving off the African coast. These observations, along with those available from the World Weather Watch, provide an opportunity to carry out numerical weather prediction (NWP) studies over West Africa utilizing high resolution limited area models.

  4. Extreme ultraviolet interferometry

    SciTech Connect

    Goldberg, Kenneth A.

    1997-12-01

    EUV lithography is a promising and viable candidate for circuit fabrication with 0.1-micron critical dimension and smaller. In order to achieve diffraction-limited performance, all-reflective multilayer-coated lithographic imaging systems operating near 13-nm wavelength and 0.1 NA have system wavefront tolerances of 0.27 nm, or 0.02 waves RMS. Owing to the highly-sensitive resonant reflective properties of multilayer mirrors and extraordinarily tight tolerances set forth for their fabrication, EUV optical systems require at-wavelength EUV interferometry for final alignment and qualification. This dissertation discusses the development and successful implementation of high-accuracy EUV interferometric techniques. Proof-of-principle experiments with a prototype EUV point-diffraction interferometer for the measurement of Fresnel zoneplate lenses first demonstrated sub-wavelength EUV interferometric capability. These experiments spurred the development of the superior phase-shifting point-diffraction interferometer (PS/PDI), which has been implemented for the testing of an all-reflective lithographic-quality EUV optical system. Both systems rely on pinhole diffraction to produce spherical reference wavefronts in a common-path geometry. Extensive experiments demonstrate EUV wavefront-measuring precision beyond 0.02 waves RMS. EUV imaging experiments provide verification of the high-accuracy of the point-diffraction principle, and demonstrate the utility of the measurements in successfully predicting imaging performance. Complementary to the experimental research, several areas of theoretical investigation related to the novel PS/PDI system are presented. First-principles electromagnetic field simulations of pinhole diffraction are conducted to ascertain the upper limits of measurement accuracy and to guide selection of the pinhole diameter. Investigations of the relative merits of different PS/PDI configurations accompany a general study of the most significant sources

  5. A Loschmidt cell combined with holographic interferometry for binary diffusion experiments in gas mixtures including first measurements on the argon-neon system

    NASA Astrophysics Data System (ADS)

    Buttig, D.; Vogel, E.; Bich, E.; Hassel, E.

    2011-10-01

    A new variant of the Loschmidt technique has been developed for measuring binary diffusion coefficients in gas mixtures in a temperature range from 10 to 80 °C and for pressures between 0.1 and 1 MPa. The two half cells of the thermostatted diffusion cell have a rectangular cross section and are fixed one upon the other. They can be connected and separated by means of a sliding plate provided with a pneumatically operated seal. The concentration in both half cells is determined simultaneously during the diffusion process using an optical system for holographic interferometry for each. The change in the refractive index results in an interference pattern which is recorded as a function of time. The concentrations of the diffusing components are derived by means of the Lorentz-Lorenz equation. The binary diffusion coefficients are calculated via the integrated ideal diffusion equation for the complete mole fraction range performing only a unique diffusion experiment. The performance of the apparatus is demonstrated on first measurements on the argon-neon system at 293.15 K. Separate refractive index measurements are carried out leading to values for the first refractivity virial coefficient of the pure gases with an estimated uncertainty of ±0.1%. This low uncertainty is required for the aimed uncertainty of ±0.5...1% for the diffusion measurements to determine the concentration and density dependences of the binary diffusion coefficient.

  6. Spectral modulation interferometry for quantitative phase imaging

    PubMed Central

    Shang, Ruibo; Chen, Shichao; Li, Chengshuai; Zhu, Yizheng

    2015-01-01

    We propose a spectral-domain interferometric technique, termed spectral modulation interferometry (SMI), and present its application to high-sensitivity, high-speed, and speckle-free quantitative phase imaging. In SMI, one-dimensional complex field of an object is interferometrically modulated onto a broadband spectrum. Full-field phase and intensity images are obtained by scanning along the orthogonal direction. SMI integrates the high sensitivity of spectral-domain interferometry with the high speed of spectral modulation to quantify fast phase dynamics, and its dispersive and confocal nature eliminates laser speckles. The principle and implementation of SMI are discussed. Its performance is evaluated using static and dynamic objects. PMID:25780737

  7. Speckle interferometry of asteroids

    NASA Technical Reports Server (NTRS)

    Drummond, Jack

    1988-01-01

    This final report for NASA Contract NAGw-867 consists of abstracts of the first three papers in a series of four appearing in Icarus that were funded by the preceding contract NAGw-224: (1) Speckle Interferometry of Asteroids I. 433 Eros; (2) Speckle Interferometry of Asteroids II. 532 Herculina; (3) Speckle Interferometry of Asteroids III. 511 Davida and its Photometry; and the fourth abstract attributed to NAGw-867, (4) Speckle Interferometry of Asteroids IV. Reconstructed images of 4 Vesta; and a review of the results from the asteroid interferometry program at Steward Observatory prepared for the Asteroids II book, (5) Speckle Interferometry of Asteroids. Two papers on asteroids, indirectly related to speckle interferometry, were written in part under NAGw-867. One is in press and its abstract is included here: Photometric Geodesy of Main-Belt Asteroids. II. Analysis of Lightcurves for Poles, Periods and Shapes; and the other paper, Triaxial Ellipsoid Dimensions and Rotational Pole of 2 Pallas from Two Stellar Occultations, is included in full.

  8. Phase-shift interferometry with a digital photocamera

    NASA Astrophysics Data System (ADS)

    Vannoni, Maurizio; Trivi, Marcelo; Molesini, Giuseppe

    2007-01-01

    A phase-shift interferometry experiment is proposed, working on a Twyman-Green optical configuration with additional polarization components. A guideline is provided to modern phase-shift interferometry, using concepts and laboratory equipment at the level of undergraduate optics courses.

  9. Optical tests with Bessel beam interferometry.

    PubMed

    Fortin, Mathieu; Piché, Michel; Borra, Ermanno

    2004-11-29

    In this paper we demonstrate how Bessel beam interferometry can be used to characterize the curvature of a reflecting surface. The approach is based on the fact that the intensity distribution produced by the coherent superposition of Bessel beams is a sensitive function of the relative phases between the constituting beams. We show how this phase sensitivity can translate into accurate measurements of the curvature of a wavefront. Experimental tests were made with a liquid mirror. We have also used Bessel beams to measure the precession angle of the liquid mirror. Our results show that Bessel beam interferometry is a very accurate tool for the optical testing of non-stationary surfaces and that it could be used as a general method of real-time, non-contact sensing. Bessel beam interferometry has the advantage of not requiring any reference arm that needs to be stabilized.

  10. Preview of Blackbeard interferometry

    NASA Astrophysics Data System (ADS)

    Carter, M. J.

    Blackbeard is a broadband VHF measurement satellite experiment designed and built by the Space Science and Technology Division of the Los Alamos National Laboratory. Blackbeard is a piggy-back experiment on the ALEXIS satellite to be launched into a 70 degree inclination orbit at an altitude of 750 km. The satellite experimental operation and data retrieval are controlled through a telemetry link from the Satellite Operations Center (SOC) located at Los Alamos, NM. The primary experimental objectives of Blackbeard are three-fold: (1) Study the dispersion of broad-band impulsive electromagnetic signals -- in particular, the higher-order amplitude and phase distortion due to propagation through the ionosphere. These depend on ionospheric conditions and irregularities. (2) Utilize RF interferometry and scintillation techniques in the low VHF-band to determine the size and extent of ionospheric irregularities and wave structure -- both natural and artificially induced. This narrow-band data will be used to categorize the ionospheric media as undisturbed, oscillatory, or turbulent. These parameters will then be input into transfer function simulations for broad-band propagation and compared with broad-band propagation data from Blackbeard. (3) Survey and characterize background noise in the VHF-band-consisting of (1) cataloging broadcast amplitudes and signatures and mapping their global pattern, and (2) cataloging the signatures of lightning events. Also, correlate emissions in the visible and VHF bands in an attempt to confirm broad-band RF emissions assumed to be associated with lightning.

  11. Preview of Blackbeard interferometry

    SciTech Connect

    Carter, M.J.

    1992-01-01

    Blackbeard is a broadband VHF measurements satellite experiment designed and built by the Space Science and Technology division of the Los Alamos National Laboratory. Blackbeard is a piggy-back experiment on the ALEXIS satellite to be launched into a 70 degree inclination orbit at an altitude of 750 km. The satellite experimental operation and data retrieval are controlled through a telemetry link from the Satellite Operations Center (SOC) located at Los Alamos, NM. The primary experimental objectives of Blackbeard are three-fold: (1) Study the dispersion of broad-band impulsive electromagnetic signals -- in particular, the higher-order amplitude and phase distortion due to propagation through the ionosphere. These depend on ionospheric conditions and irregularities. (2) Utilize RF interferometry and scintillation techniques in the low VHF-band to determine the size and extent of ionospheric irregularities and wave structure -- both natural and artificially induced. This narrow-band data will be used to categorize the ionospheric media as undisturbed, oscillatory, or turbulent. These parameters will then be input into transfer function simulations for broad-band propagation and compared with broad-band propagation data from Blackbeard. (3) Survey and characterize background noise in the VHF-band-consisting of (1) cataloging broadcast amplitudes and signatures and mapping their global pattern, and (2) cataloging the signatures of lightning events. Also, correlate emissions in the visible and VHF bands in an attempt to confirm broad-band RF emissions assumed to be associated with lightning.

  12. Preview of Blackbeard interferometry

    SciTech Connect

    Carter, M.J.

    1992-09-01

    Blackbeard is a broadband VHF measurements satellite experiment designed and built by the Space Science and Technology division of the Los Alamos National Laboratory. Blackbeard is a piggy-back experiment on the ALEXIS satellite to be launched into a 70 degree inclination orbit at an altitude of 750 km. The satellite experimental operation and data retrieval are controlled through a telemetry link from the Satellite Operations Center (SOC) located at Los Alamos, NM. The primary experimental objectives of Blackbeard are three-fold: (1) Study the dispersion of broad-band impulsive electromagnetic signals -- in particular, the higher-order amplitude and phase distortion due to propagation through the ionosphere. These depend on ionospheric conditions and irregularities. (2) Utilize RF interferometry and scintillation techniques in the low VHF-band to determine the size and extent of ionospheric irregularities and wave structure -- both natural and artificially induced. This narrow-band data will be used to categorize the ionospheric media as undisturbed, oscillatory, or turbulent. These parameters will then be input into transfer function simulations for broad-band propagation and compared with broad-band propagation data from Blackbeard. (3) Survey and characterize background noise in the VHF-band-consisting of (1) cataloging broadcast amplitudes and signatures and mapping their global pattern, and (2) cataloging the signatures of lightning events. Also, correlate emissions in the visible and VHF bands in an attempt to confirm broad-band RF emissions assumed to be associated with lightning.

  13. Neutron interferometry in a temperature controlled vacuum environment for the search of dark energy and other precision experiments

    NASA Astrophysics Data System (ADS)

    Saggu, Parminder; Cory, D.; Pushin, D.; Nsofini, J.; Sarenac, D.; Huber, M.; Arif, M.; Shahi, C.; Haun, R.; Snow, M.; Li, K.; Skavysh, V.; Heacock, B.; Young, A.; iNDEX Collaboration

    2015-04-01

    The neutron interferometer is a sensitive tool to study neutron interactions in materials. Vibrations, acoustic waves, and temperature gradients can introduce phase shifts and reduce the SNR. Low neutron flux and an interest in measuring increasingly smaller phases makes it necessary for experiments to run over long periods of time. Hence, the interferometer needs to have excellent phase stability. It has been shown that by using Quantum Information Algorithms, one can make the interferometer insensitive to vibrations. In this work, we are trying to remove phase instability due to T variations. At the NCNR, the interferometer has been placed inside a vacuum chamber to decouple it from the environment and increase overall temperature stability. An Al vacuum chamber was machined and assembled to test the concept of an interferometer in vacuum and measure phase stability with the ultimate goal of using an interferometer in vacuum in an experiment searching for dark energy.

  14. Nonclassicality Criteria in Multiport Interferometry

    NASA Astrophysics Data System (ADS)

    Rigovacca, L.; Di Franco, C.; Metcalf, B. J.; Walmsley, I. A.; Kim, M. S.

    2016-11-01

    Interference lies at the heart of the behavior of classical and quantum light. It is thus crucial to understand the boundaries between which interference patterns can be explained by a classical electromagnetic description of light and which, on the other hand, can only be understood with a proper quantum mechanical approach. While the case of two-mode interference has received a lot of attention, the multimode case has not yet been fully explored. Here we study a general scenario of intensity interferometry: we derive a bound on the average correlations between pairs of output intensities for the classical wavelike model of light, and we show how it can be violated in a quantum framework. As a consequence, this violation acts as a nonclassicality witness, able to detect the presence of sources with sub-Poissonian photon-number statistics. We also develop a criterion that can certify the impossibility of dividing a given interferometer into two independent subblocks.

  15. Deep Wideband Single Pointings and Mosaics in Radio Interferometry: How Accurately Do We Reconstruct Intensities and Spectral Indices of Faint Sources?

    NASA Astrophysics Data System (ADS)

    Rau, U.; Bhatnagar, S.; Owen, F. N.

    2016-11-01

    Many deep wideband wide-field radio interferometric surveys are being designed to accurately measure intensities, spectral indices, and polarization properties of faint source populations. In this paper, we compare various wideband imaging methods to evaluate the accuracy to which intensities and spectral indices of sources close to the confusion limit can be reconstructed. We simulated a wideband single-pointing (C-array, L-Band (1-2 GHz)) and 46-pointing mosaic (D-array, C-Band (4-8 GHz)) JVLA observation using a realistic brightness distribution ranging from 1 μJy to 100 mJy and time-, frequency-, polarization-, and direction-dependent instrumental effects. The main results from these comparisons are (a) errors in the reconstructed intensities and spectral indices are larger for weaker sources even in the absence of simulated noise, (b) errors are systematically lower for joint reconstruction methods (such as Multi-Term Multi-Frequency-Synthesis (MT-MFS)) along with A-Projection for accurate primary beam correction, and (c) use of MT-MFS for image reconstruction eliminates Clean-bias (which is present otherwise). Auxiliary tests include solutions for deficiencies of data partitioning methods (e.g., the use of masks to remove clean bias and hybrid methods to remove sidelobes from sources left un-deconvolved), the effect of sources not at pixel centers, and the consequences of various other numerical approximations within software implementations. This paper also demonstrates the level of detail at which such simulations must be done in order to reflect reality, enable one to systematically identify specific reasons for every trend that is observed, and to estimate scientifically defensible imaging performance metrics and the associated computational complexity of the algorithms/analysis procedures. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  16. Patients' experiences of being in an intensive care unit: a select literature review.

    PubMed

    Stein-Parbury, J; McKinley, S

    2000-01-01

    A total of 26 research studies on patients' experiences of being in an intensive care unit were reviewed. The studies were selected because they focused on experiences typical in intensive care units. Many patients recalled their time in the intensive care unit, sometimes in vivid detail. Patients recalled not only experiences that were negative but also ones that were neutral and even positive. Positive experiences included a sense of safety and security promoted especially by nurses. Negative experiences included impaired cognitive functioning and discomforts such as problems with sleeping, pain, and anxiety. The review indicates steps critical care staff can take to develop better ways to understand patients' experiences. Meeting such challenges can improve the quality of patients' experiences and reduce anxiety and may offset potential adverse effects of being a patient in an intensive care unit.

  17. Correlating Sampling and Intensity Statistics in Nanoparticle Diffraction Experiments

    SciTech Connect

    Ozturk, Hande; Yan, Hanfei; Hill, John P.; Noyan, I. Cevdet

    2015-08-01

    In this article, [Öztürk, Yan, Hill & Noyan (2014). J. Appl. Cryst. 47, 1016-1025] it was shown that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye-Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys. (1948), 19, 742-753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) the one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. Three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos [theta], to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos [theta]B/cos [theta], corrects this problem.

  18. Correlating sampling and intensity statistics in nanoparticle diffraction experiments

    DOE PAGES

    Öztürk, Hande; Yan, Hanfei; Hill, John P.; ...

    2015-07-28

    It is shown in a previous article [Öztürk, Yan, Hill & Noyan (2014).J. Appl. Cryst.47, 1016–1025] that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye–Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) themore » one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. For example, three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos θ, to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos θB/cos θ, corrects this problem.« less

  19. High-precision self-adaptive phase-calibration method for wavelength-tuning interferometry

    NASA Astrophysics Data System (ADS)

    Zhu, Xueliang; Zhao, Huiying; Dong, Longchao; Wang, Hongjun; Liu, Bingcai; Yuan, Daocheng; Tian, Ailing; Wang, Fangjie; Zhang, Chupeng; Ban, Xinxing

    2017-03-01

    We introduce a high-precision self-adaptive phase-calibration method for performing wavelength-tuning interferometry. Our method is insensitive to the nonlinearity of the phase shifter, even under random control. Intensity errors derived from laser voltage changes can be restrained by adopting this approach. Furthermore, this method can effectively overcome the influences from the background and modulation intensities in the interferogram, regardless of the phase structure. Numerical simulations and experiments are implemented to verify the validity of this high-precision calibration method.

  20. Virtual shearing interferometry by digital holography

    NASA Astrophysics Data System (ADS)

    Cai, L. Z.; Meng, X. F.; Wang, Y. R.; Shen, X. X.; Dong, G. Y.; Yang, X. L.

    2006-03-01

    A novel method of virtual shearing interferometry (VSI) is proposed. In this method, the shearogram is obtained by interference of a real object wave-front and a virtual object wave-front. The former is optically recorded and then digitally reconstructed; and the latter is introduced digitally by repositioning or reforming the former. The obvious advantages of VSI over conventional shearing interferometry (SI) are its versatility, accuracy, and simplicity. Only one real field is necessary to produce shearogram; there is no need of any real shearing device or even the phase unwrapping computation; and the digital shear can take any possible form according to different purposes. Both the optical experiments and computer simulations with lateral shearing, 180° rotational shearing and double lateral shearing for evaluation of lens aberrations in the general case including spherical aberration, coma, astigmatism, defocus, and tilts based on phase-shifting interferometry are given to verify the effectiveness of this method.

  1. Correlating sampling and intensity statistics in nanoparticle diffraction experiments

    SciTech Connect

    Öztürk, Hande; Yan, Hanfei; Hill, John P.; Noyan, I. Cevdet

    2015-07-28

    It is shown in a previous article [Öztürk, Yan, Hill & Noyan (2014).J. Appl. Cryst.47, 1016–1025] that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye–Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) the one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. For example, three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos θ, to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos θB/cos θ, corrects this problem.

  2. Bandwidth in bolometric interferometry

    NASA Astrophysics Data System (ADS)

    Charlassier, R.; Bunn, E. F.; Hamilton, J.-Ch.; Kaplan, J.; Malu, S.

    2010-05-01

    Context. Bolometric interferometry is a promising new technology with potential applications to the detection of B-mode polarization fluctuations of the cosmic microwave background (CMB). A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers to be competitive with imaging experiments. A crucial concern is that interferometers are assumed to be significantly affected by a spoiling effect known as bandwidth smearing. Aims: We investigate how the bandwidth modifies the work principle of a bolometric interferometer and affects its sensitivity to the CMB angular power spectra. Methods: We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. If the phase shifters produce shifts that are constant with respect to frequency, the instrument works like its monochromatic version (the modulation matrix is not modified), while if they vary (linearly or otherwise) with respect to frequency, one has to perform a special reconstruction scheme, which allows the visibilities to be reconstructed in frequency subbands. Using an angular power spectrum estimator that accounts for the bandwidth, we finally calculate the sensitivity of a broadband bolometric interferometer. A numerical simulation is performed that confirms the analytical results. Results: We conclude that (i) broadband bolometric interferometers allow broadband visibilities to be reconstructed regardless of the type of phase shifters used and (ii) for dedicated B-mode bolometric interferometers, the sensitivity loss caused by bandwidth smearing is quite acceptable, even for wideband instruments (a factor of 2 loss for a typical 20% bandwidth experiment).

  3. An evaluation of water vapor radiometer data for calibration of the wet path delay in very long baseline interferometry experiments

    NASA Technical Reports Server (NTRS)

    Kuehn, C. E.; Himwich, W. E.; Clark, T. A.; Ma, C.

    1991-01-01

    The internal consistency of the baseline-length measurements derived from analysis of several independent VLBI experiments is an estimate of the measurement precision. The paper investigates whether the inclusion of water vapor radiometer (WVR) data as an absolute calibration of the propagation delay due to water vapor improves the precision of VLBI baseline-length measurements. The paper analyzes 28 International Radio Interferometric Surveying runs between June 1988 and January 1989; WVR measurements were made during each session. The addition of WVR data decreased the scatter of the length measurements of the baselines by 5-10 percent. The observed reduction in the scatter of the baseline lengths is less than what is expected from the behavior of the formal errors, which suggest that the baseline-length measurement precision should improve 10-20 percent if WVR data are included in the analysis. The discrepancy between the formal errors and the baseline-length results can be explained as the consequence of systematic errors in the dry-mapping function parameters, instrumental biases in the WVR and the barometer, or both.

  4. An evaluation of water vapor radiometer data for calibration of the wet path delay in very long baseline interferometry experiments

    NASA Technical Reports Server (NTRS)

    Kuehn, C. E.; Himwich, W. E.; Clark, T. A.; Ma, C.

    1991-01-01

    The internal consistency of the baseline-length measurements derived from analysis of several independent VLBI experiments is an estimate of the measurement precision. The paper investigates whether the inclusion of water vapor radiometer (WVR) data as an absolute calibration of the propagation delay due to water vapor improves the precision of VLBI baseline-length measurements. The paper analyzes 28 International Radio Interferometric Surveying runs between June 1988 and January 1989; WVR measurements were made during each session. The addition of WVR data decreased the scatter of the length measurements of the baselines by 5-10 percent. The observed reduction in the scatter of the baseline lengths is less than what is expected from the behavior of the formal errors, which suggest that the baseline-length measurement precision should improve 10-20 percent if WVR data are included in the analysis. The discrepancy between the formal errors and the baseline-length results can be explained as the consequence of systematic errors in the dry-mapping function parameters, instrumental biases in the WVR and the barometer, or both.

  5. LISA Long-Arm Interferometry

    NASA Technical Reports Server (NTRS)

    Thorpe, James I.

    2009-01-01

    An overview of LISA Long-Arm Interferometry is presented. The contents include: 1) LISA Interferometry; 2) Constellation Design; 3) Telescope Design; 4) Constellation Acquisition; 5) Mechanisms; 6) Optical Bench Design; 7) Phase Measurement Subsystem; 8) Phasemeter Demonstration; 9) Time Delay Interferometry; 10) TDI Limitations; 11) Active Frequency Stabilization; 12) Spacecraft Level Stabilization; 13) Arm-Locking; and 14) Embarassment of Riches.

  6. Simulations for single-dish intensity mapping experiments

    NASA Astrophysics Data System (ADS)

    Bigot-Sazy, M.-A.; Dickinson, C.; Battye, R. A.; Browne, I. W. A.; Ma, Y.-Z.; Maffei, B.; Noviello, F.; Remazeilles, M.; Wilkinson, P. N.

    2015-12-01

    H I intensity mapping is an emerging tool to probe dark energy. Observations of the redshifted H I signal will be contaminated by instrumental noise, atmospheric and Galactic foregrounds. The latter is expected to be four orders of magnitude brighter than the H I emission we wish to detect. We present a simulation of single-dish observations including an instrumental noise model with 1/f and white noise, and sky emission with a diffuse Galactic foreground and H I emission. We consider two foreground cleaning methods: spectral parametric fitting and principal component analysis. For a smooth frequency spectrum of the foreground and instrumental effects, we find that the parametric fitting method provides residuals that are still contaminated by foreground and 1/f noise, but the principal component analysis can remove this contamination down to the thermal noise level. This method is robust for a range of different models of foreground and noise, and so constitutes a promising way to recover the H I signal from the data. However, it induces a leakage of the cosmological signal into the subtracted foreground of around 5 per cent. The efficiency of the component separation methods depends heavily on the smoothness of the frequency spectrum of the foreground and the 1/f noise. We find that as long as the spectral variations over the band are slow compared to the channel width, the foreground cleaning method still works.

  7. Birth Tourism and Neonatal Intensive Care: A Children's Hospital Experience.

    PubMed

    Mikhael, Michel; Cleary, John P; Dhar, Vijay; Chen, Yanjun; Nguyen, Danh V; Chang, Anthony C

    2016-12-01

    Objective The aim of this article is to examine characteristics of birth tourism (BT) neonates admitted to a neonatal intensive care unit (NICU). Methods This was a retrospective review over 3 years; BT cases were identified, and relevant perinatal, medical, social, and financial data were collected and compared with 100 randomly selected non-birth tourism neonates. Results A total of 46 BT neonates were identified. They were more likely to be born to older women (34 vs. 29 years; p < 0.001), via cesarean delivery (72 vs. 48%; p = 0.007), and at a referral facility (80 vs. 32%; p < 0.001). BT group had longer hospital stay (15 vs. 7 days; p = 0.02), more surgical intervention (50 vs. 21%; p < 0.001), and higher hospital charges (median $287,501 vs. $103,105; p = 0.003). One-third of BT neonates were enrolled in public health insurance program and four BT neonates (10%) were placed for adoption. Conclusion Families of BT neonates admitted to the NICU face significant challenges. Larger studies are needed to better define impacts on families, health care system, and society.

  8. Optical Long Baseline Interferometry

    NASA Astrophysics Data System (ADS)

    Le Bouquin, Jean-Baptiste

    Optical Long Baseline Interferometry provides unrivalled angular resolution on bright and compact astrophysical sources. The link between the observables (interferometric phase and contrast) and the image of the source is a Fourier transform expressed first by van Cittert and Zernike. Depending on the source size and the amount of information collected, the analysis of these Fourier components allows a measurement of the typical source size, a parametric modelling of its spatial structures, or a model-independent image reconstruction to be carried. In the past decades, optical long baseline interferometry provided fundamental measurements for astronomy (ex. Cepheids distances, surface-brightness relations) as well as iconic results such as the first images of stellar surfaces other than the Sun. Optical long baseline interferometers exist in the Northern and Southern hemisphere and are open to the astronomical community with modern level of support. We provide in this chapter an introduction to the fundamental principles of optical interferometry and introduce the currently available facilities.

  9. Simultaneous immersion Mirau interferometry

    PubMed Central

    Lyulko, Oleksandra V.; Randers-Pehrson, Gerhard; Brenner, David J.

    2013-01-01

    A novel technique for label-free imaging of live biological cells in aqueous medium that is insensitive to ambient vibrations is presented. This technique is a spin-off from previously developed immersion Mirau interferometry. Both approaches utilize a modified Mirau interferometric attachment for a microscope objective that can be used both in air and in immersion mode, when the device is submerged in cell medium and has its internal space filled with liquid. While immersion Mirau interferometry involves first capturing a series of images, the resulting images are potentially distorted by ambient vibrations. Overcoming these serial-acquisition challenges, simultaneous immersion Mirau interferometry incorporates polarizing elements into the optics to allow simultaneous acquisition of two interferograms. The system design and production are described and images produced with the developed techniques are presented. PMID:23742552

  10. Commissioning and first results of the Intense Beam EXperiment (IBEX) linear Paul trap

    NASA Astrophysics Data System (ADS)

    Sheehy, S. L.; Carr, E. J.; Martin, L. K.; Budzik, K.; Kelliher, D. J.; Machida, S.; Prior, C. R.

    2017-07-01

    The Intense Beam Experiment (IBEX) is a linear Paul trap designed to replicate the dynamics of intense particle beams in accelerators. Similar to the S-POD apparatus at Hiroshima University, IBEX is a small scale experiment which has been constructed and recently commissioned at the STFC Rutherford Appleton Laboratory in the UK. The aim of the experiment is to support theoretical studies of next-generation high intensity proton and ion accelerators, complementing existing computer simulation approaches. Here we report on the status of commissioning and first results obtained.

  11. Interferometry science center

    NASA Technical Reports Server (NTRS)

    Sargent, A. I.

    2002-01-01

    The Interferometry Science Center (ISC) is operated jointly by Caltech and JPL and is part of NASA's Navigator Program. The ISC has been created to facilitate the timely and successful execution of scientific investigations within the Navigator program, particularly those that rely on observations from NASA's interferometer projects. Currently, ISC is expected to provide full life cycle support for the Keck Interferometer, the Starlight mission, the Space Interferometry Mission, and the Terrestrial Planet Finder Mission. The nature and goals of ISc will be described.

  12. Interferometry science center

    NASA Technical Reports Server (NTRS)

    Sargent, A. I.

    2002-01-01

    The Interferometry Science Center (ISC) is operated jointly by Caltech and JPL and is part of NASA's Navigator Program. The ISC has been created to facilitate the timely and successful execution of scientific investigations within the Navigator program, particularly those that rely on observations from NASA's interferometer projects. Currently, ISC is expected to provide full life cycle support for the Keck Interferometer, the Starlight mission, the Space Interferometry Mission, and the Terrestrial Planet Finder Mission. The nature and goals of ISc will be described.

  13. 2013 Interferometry Forum Report

    NASA Astrophysics Data System (ADS)

    van Belle, G.; Ridgway, S.; ten Brummelaar, T.

    2014-04-01

    The 2013 Interferometry Forum was organized around a list of topics - each topic had a moderator and an archivist. Each participant in the forum had one or more assignments - this was not a meeting for passive participation. The following summaries are a slightly edited version of those notes; conclusions and recommendations are presented at the end of the document(An expanded version of the Forum Report may be found online at the IAU Commission 54 website, http://iau-c54.wikispaces.com/2013+Interferometry+Forum).

  14. Phase-Shifted Laser Feedback Interferometry

    NASA Technical Reports Server (NTRS)

    Ovryn, Benjie

    1999-01-01

    Phase-shifted, laser feedback interferometry is a new diagnostic tool developed at the NASA Lewis Research Center under the Advanced Technology Development (ATD) Program directed by NASA Headquarters Microgravity Research Division. It combines the principles of phase-shifting interferometry (PSI) and laser-feedback interferometry (LFI) to produce an instrument that can quantify both optical path length changes and sample reflectivity variations. In a homogenous medium, the optical path length between two points is the product of the index of refraction and the geometric distance between the two points. LFI differs from other forms of interferometry by using the laser as both the source and the phase detector. In LFI, coherent feedback of the incident light either reflected directly from a surface or reflected after transmission through a region of interest will modulate the output intensity of the laser. The combination of PSI and LFI has produced a robust instrument, based on a low-power helium-neon (HeNe) gas laser, with a high dynamic range that can be used to measure either static or oscillatory changes of the optical path length. Small changes in optical path length are limited by the fraction of a fringe that can be measured; we can measure nonoscillatory changes with a root mean square (rms) error of the wavelength/1000 without averaging.

  15. Correction of dephasing oscillations in matter-wave interferometry

    NASA Astrophysics Data System (ADS)

    Rembold, A.; Schütz, G.; Chang, W. T.; Stefanov, A.; Pooch, A.; Hwang, I. S.; Günther, A.; Stibor, A.

    2014-03-01

    Vibrations, electromagnetic oscillations, and temperature drifts are among the main reasons for dephasing in matter-wave interferometry. Sophisticated interferometry experiments, e.g., with ions or heavy molecules, often require integration times of several minutes due to the low source intensity or the high velocity selection. Here we present a scheme to suppress the influence of such dephasing mechanisms—especially in the low-frequency regime—by analyzing temporal and spatial particle correlations available in modern detectors. Such correlations can reveal interference properties that would otherwise be washed out due to dephasing by external oscillating signals. The method is shown experimentally in a biprism electron interferometer where a perturbing oscillation is artificially introduced by a periodically varying magnetic field. We provide a full theoretical description of the particle correlations where the perturbing frequency and amplitude can be revealed from the disturbed interferogram. The original spatial fringe pattern without the perturbation can thereby be restored. The technique can be applied to lower the general noise requirements in matter-wave interferometers. It allows for the optimization of electromagnetic shielding and decreases the efforts for vibrational or temperature stabilization.

  16. Systematic review of qualitative studies exploring parental experiences in the Neonatal Intensive Care Unit.

    PubMed

    Al Maghaireh, Dua'a Fayiz; Abdullah, Khatijah Lim; Chan, Chong Mei; Piaw, Chua Yan; Al Kawafha, Mariam Mofleh

    2016-10-01

    To determine the feasibility and utility of a thematic analysis approach to synthesising qualitative evidence about parental experiences in the neonatal intensive care unit. Admission of infants to the neonatal intensive care unit is usually an unexpected event for parents who can cause them to experience psychosocial difficulties. A qualitative systematic review is the best method for exploring these parents' experiences regarding this type of admission. Systematic review. Qualitative studies in peer-reviewed journals aimed at understanding parental experiences regarding infant neonatal intensive care unit admission were identified in six electronic databases. Three reviewers selected relevant articles and assessed the quality of the methodological studies using the Critical Appraisal Skills Programme. A thematic analysis approach was used to identify the most common themes in the studies describing parental experiences in the neonatal intensive care unit. A total of eighty articles were identified; nine studies were included in this review. Four studies used semistructured interviews, three used interviews, one used self-reporting and one used both focus group and interview methodologies. Common themes across parents' experiences were the stress of hospitalisation, alteration in parenting roles and the impact of infant hospitalisation on psychological health. Having an infant hospitalised in the neonatal intensive care unit is a stressful experience for parents. This experience is the result of exposure to different stressors related to the infant's condition, an alteration in parenting roles or the neonatal intensive care unit environment and staffing. These parents suffered negative psychological effects, experienced an interrupted development of a healthy parent-infant attachment and/or felt parental role alteration. The study's findings are crucial for neonatal intensive care unit nurses to develop intervention strategies and programmes that help parents to

  17. Status and plans for recoil separators for experiments with intense stable beams from ATLAS

    NASA Astrophysics Data System (ADS)

    Seweryniak, D.

    2013-12-01

    The Argonne fragment mass analyzer (FMA) has been a very important component of the experimental program at the ATLAS facility for many years and is expected to be a viable instrument for experiments with more intense beams which will become available when the ATLAS intensity upgrade is completed. Several upgrades of FMA itself and of the FMA detector suite in preparation for high-intensity beams will be presented. To accommodate experiments with extremely low cross sections, such as studies of super-heavy nuclei, construction of the Argonne gas-filled analyzer (AGFA), which will be complementary to FMA, was proposed. The design considerations for AGFA will be discussed.

  18. Chemical Actinometry: Using o-Nitrobenzaldehyde to Measure Lamp Intensity in Photochemical Experiments

    NASA Astrophysics Data System (ADS)

    Willett, Kristine L.; Hites, Ronald A.

    2000-07-01

    A simple actinometry experiment that could be used in graduate or undergraduate laboratory courses is described. The photochemical reaction of o-nitrobenzaldehyde (NBA) irradiated with a medium-pressure mercury vapor lamp is used to calculate the intensity of light over the wavelength range of 300-410 nm. The reactant disappearance rate can be quantitated by gas chromatography or by gas chromatographic mass spectrometry. The calculations necessary to convert the kinetic measurements to intensity are discussed. This experiment provides an easy way to determine the intensity of different light sources over a specific wavelength range, information that could be necessary in studying various environmentally relevant photochemical reactions.

  19. Stimulus intensity determines experience-dependent modifications in neocortical neuron firing rates

    PubMed Central

    Glazewski, Stanislaw; Barth, Alison L

    2015-01-01

    Although subthreshold inputs of neocortical sensory neurons are broadly tuned, the spiking output is more restricted. These subthreshold inputs provide a substrate for stimulus intensity-dependent changes their spiking output, as well as for experience-dependent plasticity to alter firing properties. Here we investigated how different stimulus intensities modified the firing output of individual neurons in layer 2/3 of the mouse barrel cortex. Decreasing stimulus intensity over a 30-fold range lowered the firing rates evoked by principal whisker stimulation and reduced the overall size of the responding ensemble in whisker-undeprived animals. We then examined how these responses were changed after single-whisker experience (SWE). After 7 days of SWE, the mean magnitude of response to spared whisker stimulation at the highest stimulus intensity was not altered. However, lower-intensity whisker stimulation revealed a more than 10-fold increase in mean firing output compared with control animals. Also, under control conditions, only ∽15% of neurons showed any firing at low stimulus intensity, compared with more than 70% of neurons after SWE. However, response changes measured in the immediately surrounding representations were detected only for the highest stimulus intensity. Overall, these data showed that the measurement of experience-dependent changes in the spike output of neocortical neurons was highly dependent upon stimulus intensity. PMID:25546174

  20. Decoherence-free neutron interferometry

    SciTech Connect

    Pushin, D. A.; Cory, D. G.; Arif, M.

    2009-05-15

    Perfect single-crystal neutron interferometers are adversely sensitive to environmental disturbances, particularly mechanical vibrations. The sensitivity to vibrations results from the slow velocity of thermal neutrons and the long measurement time that are encountered in a typical experiment. Consequently, to achieve a good interference solutions for reducing vibration other than those normally used in optical experiments must be explored. Here we introduce a geometry for a neutron interferometer that is less sensitive to low-frequency vibrations. This design may be compared with both dynamical decoupling methods and decoherence-free subspaces that are described in quantum information processing. By removing the need for bulky vibration isolation setups, this design will make it easier to adopt neutron interferometry to a wide range of applications and increase its sensitivity.

  1. The experience of intensive care nurses caring for patients with delirium: A phenomenological study.

    PubMed

    LeBlanc, Allana; Bourbonnais, Frances Fothergill; Harrison, Denise; Tousignant, Kelly

    2017-10-06

    The purpose of this research was to seek to understand the lived experience of intensive care nurses caring for patients with delirium. The objectives of this inquiry were: 1) To examine intensive care nurses' experiences of caring for adult patients with delirium; 2) To identify factors that facilitate or hinder intensive care nurses caring for these patients. This study utilised an interpretive phenomenological approach as described by van Manen. Individual conversational interviews were conducted with eight intensive care nurses working in a tertiary level, university-affiliated hospital in Canada. The essence of the experience of nurses caring for patients with delirium in intensive care was revealed to be finding a way to help them come through it. Six main themes emerged: It's Exhausting; Making a Picture of the Patient's Mental Status; Keeping Patients Safe: It's aReally Big Job; Everyone Is Unique; Riding It Out With Families and Taking Every Experience With You. The findings contribute to an understanding of how intensive care nurses help patients and their families through this complex and distressing experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Empowerment in intensive care: patient experiences compared to next of kin and staff beliefs.

    PubMed

    Wåhlin, Ingrid; Ek, Anna-Christina; Idvall, Ewa

    2009-12-01

    Experiences of critically ill patients are an important aspect of the quality of care in intensive care units. If next of kin and staff try to empower the patient, this is probably performed in accordance with their beliefs about what patients experience as empowering. As intensive care patients often have difficulties communicating, staff and next of kin need to interpret their wishes, but there is limited knowledge about how correct picture next of kin and staff have of the intensive care patient's experiences. The aim of this study was to compare intensive care patients' experiences of empowerment with next of kin and staff beliefs. Interviews with 11 intensive care patients, 12 next of kin and 12 staff were conducted and analysed using a content analysis method. The findings showed that the main content is quite similar between patient experiences, next of kin beliefs and staff beliefs, but a number of important differences were identified. Some of these differences were regarding how joy of life and the will to fight were generated, the character of relationships, teamwork, humour, hope and spiritual experiences. Staff and next of kin seemed to regard the patient as more unconscious than the patient him/herself did.

  3. Market variations in intensity of Medicare service use and beneficiary experiences with care.

    PubMed

    Mittler, Jessica N; Landon, Bruce E; Fisher, Elliot S; Cleary, Paul D; Zaslavsky, Alan M

    2010-06-01

    Examine associations between patient experiences with care and service use across markets. Medicare fee-for-service (FFS) and managed care (Medicare Advantage [MA]) beneficiaries in 306 markets from the 2003 Consumer Assessments of Healthcare Providers and Systems (CAHPS) surveys. Resource use intensity is measured by the 2003 end-of-life expenditure index. We estimated correlations and linear regressions of eight measures of case-mix-adjusted beneficiary experiences with intensity of service use across markets. We merged CAHPS data with service use data, excluding beneficiaries under 65 years of age or receiving Medicaid. Overall, higher intensity use was associated (p<.05) with worse (seven measures) or no better care experiences (two measures). In higher-intensity markets, Medicare FFS and MA beneficiaries reported more problems getting care quickly and less helpful office staff. However, Medicare FFS beneficiaries in higher-intensity markets reported higher overall ratings of their personal physician and main specialist. Medicare MA beneficiaries in higher-intensity markets also reported worse quality of communication with physicians, ability to get needed care, and overall ratings of care. Medicare beneficiaries in markets characterized by high service use did not report better experiences with care. This trend was strongest for those in managed care.

  4. Digitally Enhanced Heterodyne Interferometry

    NASA Technical Reports Server (NTRS)

    Shaddock, Daniel; Ware, Brent; Lay, Oliver; Dubovitsky, Serge

    2010-01-01

    Spurious interference limits the performance of many interferometric measurements. Digitally enhanced interferometry (DEI) improves measurement sensitivity by augmenting conventional heterodyne interferometry with pseudo-random noise (PRN) code phase modulation. DEI effectively changes the measurement problem from one of hardware (optics, electronics), which may deteriorate over time, to one of software (modulation, digital signal processing), which does not. DEI isolates interferometric signals based on their delay. Interferometric signals are effectively time-tagged by phase-modulating the laser source with a PRN code. DEI improves measurement sensitivity by exploiting the autocorrelation properties of the PRN to isolate only the signal of interest and reject spurious interference. The properties of the PRN code determine the degree of isolation.

  5. A LISA Interferometry Primer

    NASA Technical Reports Server (NTRS)

    Thorpe, James Ira

    2010-01-01

    A key challenge for all gravitational wave detectors in the detection of changes in the fractional difference between pairs of test masses with sufficient precision to measure astrophysical strains with amplitudes on the order of approx.10(exp -21). ln the case of the five million km arms of LISA, this equates to distance measurements on the ten picometer level. LISA interferometry utilizes a decentralized topology, in which each of the sciencecraft houses its own light sources, detectors, and electronics. The measurements made at each of the sciencecraft are then telemetered to ground and combined to extract the strain experienced by the constellation as a whole. I will present an overview of LISA interferometry and highlight some of the key components and technologies that make it possible.

  6. Quantitative comparison of experiment and theory for intense ultrashort laser-induced dissociation of H2^+

    NASA Astrophysics Data System (ADS)

    Sayler, A. M.; Anis, F.; McKenna, J.; Gaire, B.; Johnson, Nora G.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.

    2008-05-01

    Experimental measurements and theoretical calculations for intense ultrashort pulse laser-induced dissociation of H2^+ were performed under near identical conditions producing results for quantitative comparison. The 3D momentum distribution was measured for the fragments of an H2^+ beam after interaction with 10 fs, 790 nm pulses at intensities of 10^14, 10^13, and 10^12 W/cm^2. In parallel, the time-dependent Schr"odinger equation was solved in the Born-Oppenheimer representation including nuclear, rotational, and electronic excitation. To obtain angularly-resolved kinetic energy release distributions necessary to compare to measurements, the final wavefunctions, projected onto the scattering states, are averaged over the vibrational state, intensity volume, and thermal distribution appropriate to the experiment. The results of these measurements and calculations are contrasted, testing the quantitative agreement of theory and experiment for ultrashort pulses at these intensities.

  7. Two color holographic interferometry for microgravity application

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.

    1993-01-01

    Holographic interferometry is a primary candidate for the measurement of temperature and concentration in various crystal growth experiments destined for space. The method measures refractive index changes in the experiment test cell. A refractive index change can be caused by concentration changes, temperature changes, or a combination of temperature and concentration changes. If the refractive index changes are caused by temperature and concentration changes occurring simultaneously in the experiment test cell, the contributions by the two effects cannot be separated by conventional measurement methods. By using two wavelengths, two independent interferograms can be produced from the reconstruction of the hologram. The two interferograms will be different due to dispersion properties of fluid materials. These differences provide the additional information that allows the separation of simultaneously occurring temperature and concentration gradients. There is no other technique available that can provide this type of information. The primary objectives of this effort are to experimentally verify the mathematical theory of two color holographic interferometry and to determine the practical value of this technique for space application. To achieve these objectives, the accuracy and sensitivity of the technique must be determined for geometry's and materials that are relevant to the Materials Processing in the Space program of NASA. This will be achieved through the use of a specially designed two-color holographic interferometry breadboard optical system. In addition to experiments to achieve the primary goals, the breadboard will also provide inputs to the design of an optimum space flight system.

  8. Time-average dynamic speckle interferometry

    NASA Astrophysics Data System (ADS)

    Vladimirov, A. P.

    2014-05-01

    For the study of microscopic processes occurring at structural level in solids and thin biological objects, a method of dynamic speckle interferometry successfully applied. However, the method has disadvantages. The purpose of the report is to acquaint colleagues with the method of averaging in time in dynamic speckle - interferometry of microscopic processes, allowing eliminating shortcomings. The main idea of the method is the choice the averaging time, which exceeds the characteristic time correlation (relaxation) the most rapid process. The method theory for a thin phase and the reflecting object is given. The results of the experiment on the high-cycle fatigue of steel and experiment to estimate the biological activity of a monolayer of cells, cultivated on a transparent substrate is given. It is shown that the method allows real-time visualize the accumulation of fatigue damages and reliably estimate the activity of cells with viruses and without viruses.

  9. Home to die from the intensive care unit: A qualitative descriptive study of the family's experience.

    PubMed

    Hutchinson, Amy L; Van Wissen, Kim A

    2017-09-12

    Many people would choose to die at home, and this can be an option for intensive care patients. However, there is limited exploration of the impact on the family. To gain insight into family members' experiences when an adult intensive care unit patient is taken home to die. Methodology is qualitative description, utilising purposeful sampling, unstructured interviews and thematic analysis. Four participants, from two different families were interviewed. The setting was a tertiary level Intensive Care Unit in New Zealand. The experience was described as a kaleidoscope of events with two main themes: 'value' family member's found in the patient going home, and their experience of the 'process'. 'Value' subthemes: going home being the patient's own decision, home as an end-of-life environment, and the patient's positive response to being at home. 'Process' subthemes: care and support received, stress of a family member being in intensive care, feeling that everything happened quickly, and concerns and uncertainties. Going home to die from the intensive care unit can be a positive but challenging experience for the family. Full collaboration between the patient, family and staff is essential, to ensure the family are appropriately supported. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Immersion Mirau interferometry for label-free live cell imaging in an epi-illumination geometry

    PubMed Central

    Lyulko, Oleksandra V.; Randers-Pehrson, Gerhard; Brenner, David J.

    2013-01-01

    In cell biology studies it is often important to avoid the damaging effects caused by fluorescent stains or UV-light. Immersion Mirau Interferometry (IMI) is an epi-illumination label-free imaging technique developed at the Columbia University Radiological Research Accelerator Facility. It is based on the principles of phase-shifting interferometry (PSI) and represents a novel approach for interferometric imaging of living cells in medium. To accommodate the use of medium, a custom immersion Mirau interferometric attachment was designed and built in-house. The space between the reference mirror and the beam splitter is filled with liquid to ensure identical optical paths in the test and reference arms. The interferometer is mountable onto a microscope objective. The greatest limitation of standard PSI is the sensitivity to environmental vibrations, because it requires consecutive acquisition of several interferograms. We are developing Simultaneous Immersion Mirau Interferometry (SIMI), which facilitates simultaneous acquisition of all interferograms and eliminates the effects of vibration. Polarization optics, incorporated into the design, introduces a phase delay to one of the components of the test beam. This enables simultaneous creation and spatial separation of two interferograms, which are combined with the background image to reconstruct the intensity map of the specimen. Our results of imaging live and fixed cells with IMI and SIMI show that this system produces images of a quality that is sufficient to perform targeted cellular irradiation experiments. PMID:24392197

  11. Precision surveying using very long baseline interferometry

    NASA Technical Reports Server (NTRS)

    Ryan, J. W.; Clark, T. A.; Coates, R.; Ma, C.; Robertson, D. S.; Corey, B. E.; Counselman, C. C.; Shapiro, I. I.; Wittels, J. J.; Hinteregger, H. F.

    1977-01-01

    Radio interferometry measurements were used to measure the vector baselines between large microwave radio antennas. A 1.24 km baseline in Massachusetts between the 36 meter Haystack Observatory antenna and the 18 meter Westford antenna of Lincoln Laboratory was measured with 5 mm repeatability in 12 separate experiments. Preliminary results from measurements of the 3,928 km baseline between the Haystack antenna and the 40 meter antenna at the Owens Valley Radio Observatory in California are presented.

  12. Symptom experiences of family members of intensive care unit patients at high risk for dying.

    PubMed

    McAdam, Jennifer L; Dracup, Kathleen A; White, Douglas B; Fontaine, Dorothy K; Puntillo, Kathleen A

    2010-04-01

    To describe the symptom experiences of family members of patients at high risk for dying in the intensive care unit and to assess risk factors associated with higher symptom burden. Prospective, cross-sectional study. Three intensive care units at a large academic medical center. A sample of 74 family members of 74 intensive care unit patients who had a grave prognosis and were judged to be at high risk for dying. Patients at high risk for dying were identified as having Acute Physiology and Chronic Health Evaluation II scores >20, an intensive care unit length of stay >72 hrs, and being mechanically ventilated. None. We assessed the degree of symptom burden approximately 4 days after the patient's admission to the intensive care unit in the following domains: traumatic stress, anxiety, and depression. Overall, the prevalence of symptoms was high, with more than half (57%) of family members having moderate to severe levels of traumatic stress, 80% having borderline symptoms of anxiety, and 70% having borderline symptoms of depression. More than 80% of family members had other physical and emotional symptoms, such as fatigue, sadness, and fear, and these were experienced at the moderate to severe levels of distress. Factors independently associated with greater severity of symptoms included younger age, female gender, and non-white race of the family member. The only patient factor significantly associated with symptom severity was younger age. Despite their symptom experience, the majority of the family members were coping at moderate to high levels and functioning at high levels during the intensive care unit experience. We document a high prevalence of psychological and physical symptoms among family members during an intensive care unit admission. These data complement existing data on long-term symptom burden and highlight the need to improve family centered care in intensive care units.

  13. Hot electron generation and energy coupling in planar experiments with shock ignition high intensity lasers

    NASA Astrophysics Data System (ADS)

    Wei, M. S.; Krauland, C.; Alexander, N.; Zhang, S.; Peebles, J.; Beg, F. N.; Theobald, W.; Borwick, E.; Ren, C.; Yan, R.; Haberberger, D.; Betti, R.; Campbell, E. M.

    2016-10-01

    Hot electrons produced in nonlinear laser plasma interactions are critical issues for shock ignition (SI) laser fusion. We conducted planar target experiments to characterize hot electron and energy coupling using the high energy OMEGA EP laser system at SI high intensities. Targets were multilayered foils consisting of an ablator (either plastic or lithium) and a Cu layer to facilitate hot electron detection via fluorescence and bremsstrahlung measurements. The target was first irradiated by multi-kJ, low-intensity UV beams to produce a SI-relevant mm-scale hot ( 1 keV) preformed plasma. The main interaction pulse, either a kJ 1-ns UV pulse with intensity 1.6x1016 Wcm-2 or a kJ 0.1-ns IR pulse with intensity up to 2x1017 Wcm-2was injected at varied timing delays. The high intensity IR beam was found to strongly interact with underdense plasmas breaking into many filaments near the quarter critical density region followed by propagation of those filaments to critical density, producing hot electrons with Thot 70 keV in a well-contained beam. While the high intensity UV beam showed poor energy coupling. Details of the experiments and the complementary PIC modeling results will be presented. Work supported by U.S. DOE under contracts DE-NA0002730 (NLUF) and DE-SC0014666 (HEDLP).

  14. Future Looks Bright for Interferometry

    NASA Astrophysics Data System (ADS)

    2008-09-01

    First Light for the PRIMA instrument The PRIMA instrument [1] of the ESO Very Large Telescope Interferometer (VLTI) recently saw "first light" at its new home atop Cerro Paranal in Chile. When fully operational, PRIMA will boost the capabilities of the VLTI to see sources much fainter than any previous interferometers, and enable astrometric precision unmatched by any other existing astronomical facility. PRIMA will be a unique tool for the detection of exoplanets. First Light of the PRIMA Instrument ESO PR Photo 29a/08 Preparing for PRIMA "PRIMA is specifically designed to see if one star 'wobbles' to and fro because it is has unseen planetary companions", says instrument scientist Gerard van Belle. "This allows us to not only detect exoplanets, but to measure their mass." PRIMA's expected astrometric precision of tens of micro-arcseconds is unmatched by any other existing astronomical facility, whether on the ground or in orbit [2]. In addition to taking astrometric measurements PRIMA will be the key to the imaging of faint sources with the VLTI using the science instruments AMBER and MIDI. Interferometry combines the light received by two or more telescopes, concentrating on tiny differences between the signals to measure angles with exquisite precision. Using this technique PRIMA can pick out details as sharply as a single telescope with a diameter equivalent to the largest distance between the telescopes. For the VLTI, the distance between the two telescope elements is about 200 metres. The PRIMA instrument is unique amongst the VLTI instruments, in that it is effectively two interferometers in one. PRIMA will take data from two sources on the sky simultaneously: the brighter source can be used for tracking, allowing the interferometer to "stare" at the fainter source for longer than is now possible with conventional interferometers. Although there have been earlier pathfinder experiments to test this technique, PRIMA represents the first facility

  15. Spatial interferometry in optical astronomy

    NASA Technical Reports Server (NTRS)

    Gezari, Daniel Y.; Roddier, Francois; Roddier, Claude

    1990-01-01

    A bibliographic guide is presented to publications of spatial interferometry techniques applied to optical astronomy. Listings appear in alphabetical order, by first author, as well as in specific subject categories listed in chronological order, including imaging theory and speckle interferometry, experimental techniques, and observational results of astronomical studies of stars, the Sun, and the solar system.

  16. Vibration Analysis by Speckle Interferometry,

    DTIC Science & Technology

    The vibrational modes of complex systems can be visualized with high sensitivity by laser light speckle interferometry. Electronic speckle pattern...interferometry (ESPI), in contrast to holography, does not use photo-chemical storage media but shows a live image of the vibrational modes created by

  17. The MERIT (nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Efthymiopoulos, Ilias; Fabich, A.; Grudiev, A.; Haug, F.; Lettry, J.; Palm, M.; Pernegger, Heinz; Steerenberg, R.R.; Bennett, J.R.J.; Caretta, O.; Loveridge, P.; /Rutherford /Oak Ridge /Brookhaven /Princeton U. /Fermilab

    2008-06-01

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here.

  18. The MERIT(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Efthymiopoulos, I.; Fabich, A.; Palm, M.; Lettry, J.; Haug, F.; Pernegger, H.; Steerenberg, R.; Grudiev, A.; Kirk, H.g.; Tsang, t.; Mokbov, N.; /Fermilab /Oak Ridge /Princeton U. /Rutherford /SUNY, Stony Brook

    2008-06-01

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam. Preliminary results of the data analysis will be presented here.

  19. The MERIT(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Ethymiopoulos,I.; Fabich, A.; Palm, M.; Lettry, J.; Haug, F.; Pernegger, H.; Steerenberg, R.; Grudiev, A.; Kirk, H.G.; Tsang, T.; Mokhov, N.; Striganov, S.; Carroll, A.J.; Graves, V.B.; Spampinato, P.T.; McDonald, K.T.; Bennett, J.R.J.; Caretta, O.; Loveridge, P.; Park, H.

    2008-06-23

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here.

  20. Improvement of depth resolution in depth-resolved wavenumber-scanning interferometry using wavenumber-domain least-squares algorithm: comparison and experiment.

    PubMed

    Bai, Yulei; Jia, Quanjie; Zhang, Yun; Huang, Qiquan; Yang, Qiyu; Ye, Shuangli; He, Zhaoshui; Zhou, Yanzhou; Xie, Shengli

    2016-05-01

    It is important to improve the depth resolution in depth-resolved wavenumber-scanning interferometry (DRWSI) owing to the limited range of wavenumber scanning. In this work, a new nonlinear iterative least-squares algorithm called the wavenumber-domain least-squares algorithm (WLSA) is proposed for evaluating the phase of DRWSI. The simulated and experimental results of the Fourier transform (FT), complex-number least-squares algorithm (CNLSA), eigenvalue-decomposition and least-squares algorithm (EDLSA), and WLSA were compared and analyzed. According to the results, the WLSA is less dependent on the initial values, and the depth resolution δz is approximately changed from δz to δz/6. Thus, the WLSA exhibits a better performance than the FT, CNLSA, and EDLSA.

  1. Parents' Experiences during Their Infant's Transition from Neonatal Intensive Care Unit to Home: A Qualitative Study

    ERIC Educational Resources Information Center

    Hutchinson, Sharon W.; Spillet, Marydee A.; Cronin, Mary

    2012-01-01

    Limited literature exists which examines how parents of infants hospitalized in the Neonatal Intensive Care Unit (NICU) transition from their infant's NICU hospital stay to home. This study examines the question, "What are the experiences of parents during their infant's transition from the NICU to home?" Grounded theory methods served as the…

  2. Is compliance with hand disinfection in the intensive care unit related to work experience?

    PubMed

    Noritomi, Danilo Teixeira; Chierego, Marialuisa; Byl, Bauduin; Menestrina, Nicola; Carollo, Tiziana; Struelens, Marc; Vincent, Jean-Louis

    2007-03-01

    The performance of hand disinfection by staff in a 31-bed department of intensive care was monitored. During 32 hours of observation, 727 opportunities for hand disinfection were observed, and the compliance rate was 27.9%. The level of work experience was not correlated with hand disinfection compliance rates.

  3. Using Infant Massage Following a Mother's Unfavorable Neonatal Intensive Care Unit Experiences: A Case Study

    ERIC Educational Resources Information Center

    Lappin, Grace

    2005-01-01

    The purpose of this case study was to explore the synchronous behaviors enacted by mother and infant with blindness. In the study, a mother's less than optimal experience with the neonatal intensive care unit (NICU) had a profound effect not only on her and her infant son, who was born 3 months prematurely and was visually impaired, but also on…

  4. Using Infant Massage Following a Mother's Unfavorable Neonatal Intensive Care Unit Experiences: A Case Study

    ERIC Educational Resources Information Center

    Lappin, Grace

    2005-01-01

    The purpose of this case study was to explore the synchronous behaviors enacted by mother and infant with blindness. In the study, a mother's less than optimal experience with the neonatal intensive care unit (NICU) had a profound effect not only on her and her infant son, who was born 3 months prematurely and was visually impaired, but also on…

  5. Variable sensitivity moire interferometry

    NASA Technical Reports Server (NTRS)

    Johnson-Cole, Helen; Bennewitz, James H.; Gilbert, John A.

    1991-01-01

    This paper demonstrates that optical microlithography can be used to produce a crossed grating which diffracts light into multiple orders sufficient to record moire interferograms with sensitivities ranging from 2.0 to 0.285 micron/fringe. The grating profile produced by the method is analyzed to establish the diffraction efficiency in each diffraction order, and generalized expressions are given for variable sensitivity moire interferometry. Experimental tests are conducted to verify analytical arguments. In one of these tests, two different diffraction order pairs are used simultaneously to verify that surface displacement can be measured at different sensitivities.

  6. Chromatic confocal spectral interferometry

    SciTech Connect

    Papastathopoulos, Evangelos; Koerner, Klaus; Osten, Wolfgang

    2006-11-10

    Chromatic confocal spectral interferomertry (CCSI) is a novel scheme for topography measurements that combines the techniques of spectral interferometry and chromatic confocal microscopy. This hybrid method allows for white-light interferometric detection with a high NA in a single-shot manner. To the best of our knowledge, CCSI is the first interferometric method that utilizes a confocally filtered and chromatically dispersed focus for detection and simultaneously allows for retrieval of the depth position of reflecting or scattering objects utilizing the phase (modulation frequency) of the interferometric signals acquired. With the chromatically dispersed focus, the depth range of the sensor is decoupled from the NA of the microscope objective.

  7. Developments In Moire Interferometry

    NASA Astrophysics Data System (ADS)

    Post, Daniel

    1982-06-01

    Recent progress in high-sensitivity moire interferometry is reviewed. Interference patterns reveal full-field contour maps of in-plane displacements. Sensitivity corresponds to moire with 1200 lines/mm (30,480 //in.) for most examples, but approaches the theoretical limit of X/2 displacement per fringe in one demonstration. Techniques for producing cross-line phase gratings on specimens are described, as well as use of real and virtual reference gratings. Carrier patterns and optical filtering are used to cancel initial or no-load patterns. Diverse applications are illustrated.

  8. Speckle Interferometry with Amateur-Class Equipment

    NASA Astrophysics Data System (ADS)

    Harshaw, Richard; Wuthrich, Ethan; Dolbear, Kyle

    2015-05-01

    The relatively young field of speckle interferometry of close double stars has up to now been the domain of large telescopes and expensive scientific CCD cameras. With the advent of relatively inexpensive and high-performance CCD cameras, the domain of speckle interferometry has been extended into the serious amateur realm allowing amateurs with equipment as small as 8-inches aperture to do actual speckle analysis of binary star systems. This paper describes the work of one such team of amateur astronomers and students as part of their course work for an on-line scientific research experience course provided on-line by Cuesta College of San Luis Obispo, California. An explanation of speckle and how it works is followed by a discussion of how the camera was calibrated, then a discussion of the research methodology. Results of calibration and double star measurements are then given and implications of the process and results discussed.

  9. A New Neutron Interferometry Facility at NCNR

    NASA Astrophysics Data System (ADS)

    Shahi, Chandra; Wietfeldt, Fred; Huber, Michael; Pushin, Dmitry; Arif, Muhammad

    2013-10-01

    A neutron interferometer splits an incoming neutron beam into two coherent partial beams, which travel on different paths and then recombine to form an interference pattern. This pattern is used to precisely determine the phase shift of a sample in one of the paths, thus the neutron interaction potential in the sample can be measured with high precision. A new neutron interferometry setup (NIOFa) has been constructed at the NIST Center for Neutron Research (NCNR). This new facility is mainly focused on spin based interferometry, which will expand its applications in both quantum computation and material research. New spin-control mechanisms are being tested; including thin-film spin flippers and efficient polarizing double cavity super mirrors. Doubling the neutron's degrees of freedom inside the interferometer promises exciting new quantum mechanical experiments and research capabilities. This work is supported by the National Science Foundation.

  10. The critical angle in seismic interferometry

    USGS Publications Warehouse

    Van Wijk, K.; Calvert, A.; Haney, M.; Mikesell, D.; Snieder, R.

    2008-01-01

    Limitations with respect to the characteristics and distribution of sources are inherent to any field seismic experiment, but in seismic interferometry these lead to spurious waves. Instead of trying to eliminate, filter or otherwise suppress spurious waves, crosscorrelation of receivers in a refraction experiment indicate we can take advantage of spurious events for near-surface parameter extraction for static corrections or near-surface imaging. We illustrate this with numerical examples and a field experiment from the CSM/Boise State University Geophysics Field Camp.

  11. Facing death in the intensive care unit. A phenomenological study of nurses' experiences.

    PubMed

    Velarde-García, Juan Francisco; Luengo-González, Raquel; González-Hervias, Raquel; Cardenete-Reyes, César; Alvarado-Zambrano, Gema; Palacios-Ceña, Domingo

    2016-02-01

    Nurses may experience considerable emotional burden due to patient death, in part as they are generally the professionals who have the most contact with patients. To describe the lived experience of Spanish nurses working in intensive care units regarding how they face the death of their patients. A qualitative phenomenological study was performed. A purposeful sample was used. The data collection strategies used included in-depth unstructured and semi-structured interviews, field notes and personal documents. Afterwards, data were analyzed using the Giorgi proposal. 22 nurses participated, with a mean age of 40.8 years and a mean work experience of 13.8 years. Three themes were identified: 1) dealing with expectations of recovery, 2) accepting the age of death, and 3) experiencing emotional attachment. Nurses in intensive care units report a great emotional burden derived from patients death, Support programs for nurses should be organised within these units.

  12. Complex master slave interferometry.

    PubMed

    Rivet, Sylvain; Maria, Michael; Bradu, Adrian; Feuchter, Thomas; Leick, Lasse; Podoleanu, Adrian

    2016-02-08

    A general theoretical model is developed to improve the novel Spectral Domain Interferometry method denoted as Master/Slave (MS) Interferometry. In this model, two functions, g and h are introduced to describe the modulation chirp of the channeled spectrum signal due to nonlinearities in the decoding process from wavenumber to time and due to dispersion in the interferometer. The utilization of these two functions brings two major improvements to previous implementations of the MS method. A first improvement consists in reducing the number of channeled spectra necessary to be collected at Master stage. In previous MSI implementation, the number of channeled spectra at the Master stage equated the number of depths where information was selected from at the Slave stage. The paper demonstrates that two experimental channeled spectra only acquired at Master stage suffice to produce A-scans from any number of resolved depths at the Slave stage. A second improvement is the utilization of complex signal processing. Previous MSI implementations discarded the phase. Complex processing of the electrical signal determined by the channeled spectrum allows phase processing that opens several novel avenues. A first consequence of such signal processing is reduction in the random component of the phase without affecting the axial resolution. In previous MSI implementations, phase instabilities were reduced by an average over the wavenumber that led to reduction in the axial resolution.

  13. Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

    DOE PAGES

    Öztürk, Hande; Noyan, I. Cevdet

    2017-08-24

    A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

  14. Transitions in the communication experiences of tracheostomised patients in intensive care: a qualitative descriptive study.

    PubMed

    Flinterud, Stine Irene; Andershed, Birgitta

    2015-08-01

    To describe how tracheostomised patients in intensive care experience acts of communication and to better understand their experiences in the context of the transitions theory. Waking up in an intensive care unit unable to speak because of mechanical ventilation can be challenging. Communication aids are available, but patients still report difficulties communicating. Investigating how mechanically ventilated patients experience communication in the context of the transitions theory might elucidate new ways of supporting them during their transitions while being ventilated. A qualitative, descriptive design. Eleven patients who had previously been tracheostomised in an intensive care unit were included in this quality improvement project conducted in a university hospital in Norway. Participants were tracheostomised from 3-27 days. Semistructured interviews were conducted from June 2013-August 2013, 3-18 months after hospital discharge. Transcripts were analysed using inductive content analysis. Participants reported a great diversity of emotions and experiences attempting to communicate while being tracheostomised. One overarching theme emerging from the analysis was the 'Experience of caring and understanding despite having uncomfortable feelings due to troublesome communication.' The theme consists of three categories. The category 'Emotionally challenging' shows that patients struggled initially. With time, their coping improved, as revealed in the category 'The experience changes with time.' Despite difficulties, participants described positive experiences, as shown in the category 'Successful communication.' The importance of patients experiencing caring and understanding despite their difficult situation constitutes the core finding. The findings suggest that participants went through different transitions. Some reached the end of their transition, experiencing increased stability. Despite challenges with communication, participants reported that caring

  15. Validating Laser-Induced Birefringence Theory with Plasma Interferometry

    SciTech Connect

    Chen, Cecilia

    2015-09-02

    Intense laser beams crossing paths in plasma is theorized to induce birefringence in the medium, resulting from density and refractive index modulations that affect the polarization of incoming light. The goal of the associated experiment, conducted on Janus at Lawrence Livermore’s Jupiter Laser Facility, was to create a tunable laser-plasma waveplate to verify the relationship between dephasing angle and beam intensity, plasma density, plasma temperature, and interaction length. Interferometry analysis of the plasma channel was performed to obtain a density map and to constrain temperature measured from Thomson scattering. Various analysis techniques, including Fast Fourier transform (FFT) and two variations of fringe-counting, were tried because interferograms captured in this experiment contained unusual features such as fringe discontinuity at channel edges, saddle points, and islands. The chosen method is flexible, semi-automated, and uses a fringe tracking algorithm on a reduced image of pre-traced synthetic fringes. Ultimately, a maximum dephasing angle of 49.6° was achieved using a 1200 μm interaction length, and the experimental results appear to agree with predictions.

  16. Intellectual property in holographic interferometry

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya; Hunt, David

    2006-08-01

    This paper presents an overview of patents and patent applications on holographic interferometry, and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic interferometry were uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, Japanese Patent Office and Korean Patent Office for the time frame from 1971 through May 2006. The patent analysis unveils trends in patent temporal distribution, patent families formation, significant technological coverage within the market of system that employ holographic interferometry and other interesting insights.

  17. The patient experience of intensive care: a meta-synthesis of Nordic studies.

    PubMed

    Egerod, Ingrid; Bergbom, Ingegerd; Lindahl, Berit; Henricson, Maria; Granberg-Axell, Anetth; Storli, Sissel Lisa

    2015-08-01

    Sedation practices in the intensive care unit have evolved from deep sedation and paralysis toward lighter sedation and better pain management. The new paradigm of sedation has enabled early mobilization and optimized mechanical ventilator weaning. Intensive care units in the Nordic countries have been particularly close to goals of lighter or no sedation and a more humane approach to intensive care. The aim of our study was to systematically review and reinterpret newer Nordic studies of the patient experience of intensive care to obtain a contemporary description of human suffering during life-threatening illness. We conducted a meta-synthesis in which we collected, assessed, and analyzed published qualitative studies with the goal of synthesizing these findings into a new whole. Analysis was based on the scientific approach of Gadamerian hermeneutics. Nordic intensive care units. Patients in Nordic intensive care units. We performed a literature search of qualitative studies of the patient experience of intensive care based on Nordic publications in 2000-2013. We searched the following databases: PubMed, CINAHL, Scopus, and PsycINFO. Each original paper was assessed by all authors using the Critical Appraisal Skills Program instrument for qualitative research. We included 22 studies, all of which provided direct patient quotes. The overarching theme was identified as: The patient experience when existence itself is at stake. We constructed an organizing framework for analysis using the main perspectives represented in the included studies: body, mind, relationships, and ICU-environment. Final analysis and interpretation resulted in the unfolding of four themes: existing in liminality, existing in unboundedness, existing in mystery, and existing on the threshold. Our main finding was that human suffering during intensive care is still evident although sedation is lighter and the environment is more humane. Our interpretation suggested that patients with life

  18. How do patients with exacerbated chronic obstructive pulmonary disease experience care in the intensive care unit?

    PubMed Central

    Torheim, Henny; Kvangarsnes, Marit

    2014-01-01

    The aim was to gain insight into how patients with advanced chronic obstructive pulmonary disease (COPD) experience care in the acute phase. The study has a qualitative design with a phenomenological approach. The empirics consist of qualitative in-depth interviews with ten patients admitted to the intensive care units in two Norwegian hospitals. The interviews were carried out from November 2009 to June 2011. The data have been analysed through meaning condensation, in accordance with Amadeo Giorgi's four-step method. Kari Martinsen's phenomenological philosophy of nursing has inspired the study. An essential structure of the patients' experiences of care in the intensive care unit by acute COPD-exacerbation may be described as: Feelings of being trapped in a life-threatening situation in which the care system assumes control over their lives. This experience is conditioned not only by the medical treatment, but also by the entire interaction with the caregivers. The essence of the phenomenon is presented through three themes which describe the patient's lived experience: preserving the breath of life, vulnerable interactions and opportunities for better health. Acute COPD-exacerbation is a traumatic experience and the patients become particularly vulnerable when they depend on others for breathing support. The phenomenological analysis shows that the patients experience good care during breath of life preservation when the care is performed in a way that gives patients more insight into their illness and gives new opportunities for the future. PMID:24313779

  19. Moving on in life after intensive care--partners' experience of group communication.

    PubMed

    Ahlberg, Mona; Bäckman, Carl; Jones, Christina; Walther, Sten; Hollman Frisman, Gunilla

    2015-09-01

    Partners have a burdensome time during and after their partners' intensive care period. They may appear to be coping well outwardly but inside feel vulnerable and lost. Evaluated interventions for partners on this aspect are limited. The aim of this study was to describe the experience of participating in group communication with other partners of former intensive care patients. The study has a descriptive intervention-based design where group communication for partners of former, surviving intensive care unit (ICU) patients was evaluated. A strategic selection was made of adult partners to former adult intensive care patients (n = 15), 5 men and 10 women, aged 37-89 years. Two group communication sessions lasting 2 h were held at monthly intervals with three to five partners. The partners later wrote, in a notebook, about their feelings of participating in group communications. To deepen the understanding of the impact of the sessions, six of the partners were interviewed. Content analysis was used to analyse the notebooks and the interviews. Three categories were identified: (1) Emotional impact, the partners felt togetherness and experienced worries and gratitude, (2) Confirmation, consciousness through insight and reflection and (3) The meeting design, group constellation and recommendation to participate in group communication. Partners of an intensive care patient are on a journey, constantly trying to adapt to the new situation and find new strategies to ever-changing circumstances. Group communications contributed to togetherness and confirmation. To share experiences with others is one way for partners to be able to move forward in life. Group communication with other patients' partners eases the process of going through the burden of being a partner to an intensive care patient. Group communications needs to be further developed and evaluated to obtain consensus and evidence for the best practice. © 2015 British Association of Critical Care Nurses.

  20. An exploration of participants' experience of an intensive care nursing transition to specialty practice program.

    PubMed

    Madhuvu, Auxillia E; Plummer, Virginia; Morphet, Julia

    2017-09-26

    Transition to specialty practice programs were developed to support, educate and facilitate recruitment and retention of nurses in specialised areas of practice. The intensive care nursing transition to specialty practice program in this study was implemented in 2000. To date, in Australia there are no published studies which focus on intensive care nursing transition to specialty practice programs. The study aimed to explore the effects of an intensive care nursing transition to specialty practice program offered in two intensive care units in a single Australian health service. A cross-sectional survey design was used. Quantitative data were collected from nurses who participated in the transition to specialty practice program from 2005 to 2015 using an anonymous online survey. Summary statistics and Chi-square tests were used to analyse the data. The response rate was 51.8% (n=86). Most of the transition to specialty practice program participants had medical nursing experience (n=35, 40.7%) or surgical nursing experience (n=35, 40.7%) prior to enrolling into the program. More than half (n=46, 53.5%) of the participants had worked in the intensive care units for more than two years post program. The majority of the participants (n=60, 69.8%) undertook post graduate education after the transition to specialty practice program. Significant numbers of experienced nurses undertook transition to specialty practice program into intensive care and majority of the participants reported positive results of the program. Copyright © 2017 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  1. Two color holographic interferometry for microgravity application

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; Weber, David C.

    1995-01-01

    Holographic interferometry is a primary candidate for determining temperature and concentration in crystal growth experiments designed for space. The method measures refractive index changes within the fluid of an experimental test cell resulting from temperature and/or concentration changes. When the refractive index changes are caused by simultaneous temperature and concentration changes, the contributions of the two effects cannot be separated by single wavelength interferometry. By using two wavelengths, however, two independent interferograms can provide the additional independent equation required to determine the two unknowns. There is no other technique available that provides this type of information. The primary objectives of this effort were to experimentally verify the mathematical theory of two color holographic interferometry (TCHI) and to determine the practical value of this technique for space application. In the foregoing study, the theory of TCHI has been tested experimentally over a range of interest for materials processing in space where measurements of temperature and concentration in a solution are required. New techniques were developed and applied to stretch the limits beyond what could be done with existing procedures. The study resulted in the production of one of the most advanced, enhanced sensitivity holographic interferometers in existence. The interferometric measurements made at MSFC represent what is believed to be the most accurate holographic interferometric measurements made in a fluid to date. The tests have provided an understanding of the limitations of the technique in practical use.

  2. A novel type of very long baseline astronomical intensity interferometer

    NASA Astrophysics Data System (ADS)

    Borra, Ermanno F.

    2013-12-01

    This article presents a novel type of very long baseline astronomical interferometer that uses the fluctuations, as a function of time, of the intensity measured by a quadratic detector, which is a common type of astronomical detector. The theory on which the technique is based is validated by laboratory experiments. Its outstanding principal advantages comes from the fact that the angular structure of an astronomical object is simply determined from the visibility of the minima of the spectrum of the intensity fluctuations measured by the detector, as a function of the frequency of the fluctuations, while keeping the spacing between mirrors constant. This would allow a simple setup capable of high angular resolutions because it could use an extremely large baseline. Another major interest is that it allows for a more efficient use of telescope time because observations at a single baseline are sufficient, while amplitude and intensity interferometers need several observations at different baselines. The fact that one does not have to move the telescopes would also allow detecting faster time variations because having to move the telescopes sets a lower limit to the time variations that can be detected. The technique uses wave interaction effects and thus has some characteristics in common with intensity interferometry. A disadvantage of the technique, like in intensity interferometry, is that it needs strong sources if observing at high frequencies (e.g. the visible). This is a minor disadvantage in the radio region. At high frequencies, this disadvantage is mitigated by the fact that, like in intensity interferometry, the requirements of the optical quality of the mirrors used are far less severe than in amplitude interferometry so that poor quality large reflectors (e.g. Cherenkov telescopes) can be used in the optical region.

  3. [Nurses' perception, experience and knowledge of palliative care in intensive care units].

    PubMed

    Piedrafita-Susín, A B; Yoldi-Arzoz, E; Sánchez-Fernández, M; Zuazua-Ros, E; Vázquez-Calatayud, M

    2015-01-01

    Adequate provision of palliative care by nursing in intensive care units is essential to facilitate a "good death" to critically ill patients. To determine the perceptions, experiences and knowledge of intensive care nurses in caring for terminal patients. A literature review was conducted on the bases of Pubmed, Cinahl and PsicINFO data using as search terms: cuidados paliativos, UCI, percepciones, experiencias, conocimientos y enfermería and their alternatives in English (palliative care, ICU, perceptions, experiences, knowledge and nursing), and combined with AND and OR Boolean. Also, 3 journals in intensive care were reviewed. Twenty seven articles for review were selected, most of them qualitative studies (n=16). After analysis of the literature it has been identified that even though nurses perceive the need to respect the dignity of the patient, to provide care aimed to comfort and to encourage the inclusion of the family in patient care, there is a lack of knowledge of the end of life care in intensive care units' nurses. This review reveals that to achieve quality care at the end of life, is necessary to encourage the training of nurses in palliative care and foster their emotional support, to conduct an effective multidisciplinary work and the inclusion of nurses in decision making. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  4. A threat to the understanding of oneself: intensive care patients' experiences of dependency.

    PubMed

    Lykkegaard, Kristina; Delmar, Charlotte

    2013-06-28

    This study examines the meaning of dependency on care as experienced by intensive care patients. Literature on the subject is sparse, but research from nonintensive settings shows that dependency is often experienced negatively. The study is based on in-depth qualitative semistructured interviews with three former patients characterized as narratives. The analysis is inspired by a phenomenological hermeneutical method. The study has found that dependency is experienced as difficult and that the experience seems to be attached to the relationship to oneself. Patients feel powerless and experience shame, their understanding of self is threatened, and they fight for independence in the course after intensive care. The findings might be influenced by the study being conducted in a Western country setting, where independence is valued. They can be used as means of reflection on nursing practice and matters such as communication and patient participation.

  5. A threat to the understanding of oneself: Intensive care patients' experiences of dependency

    PubMed Central

    Lykkegaard, Kristina; Delmar, Charlotte

    2013-01-01

    This study examines the meaning of dependency on care as experienced by intensive care patients. Literature on the subject is sparse, but research from nonintensive settings shows that dependency is often experienced negatively. The study is based on in-depth qualitative semistructured interviews with three former patients characterized as narratives. The analysis is inspired by a phenomenological hermeneutical method. The study has found that dependency is experienced as difficult and that the experience seems to be attached to the relationship to oneself. Patients feel powerless and experience shame, their understanding of self is threatened, and they fight for independence in the course after intensive care. The findings might be influenced by the study being conducted in a Western country setting, where independence is valued. They can be used as means of reflection on nursing practice and matters such as communication and patient participation. PMID:23809023

  6. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    NASA Astrophysics Data System (ADS)

    Box, Dennis

    2014-06-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload. Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.

  7. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    SciTech Connect

    Box, Dennis

    2014-01-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload. Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.

  8. Special topics in infrared interferometry. [Michelson interferometer development

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  9. Managing Hardware Configurations and Data Products for the Canadian Hydrogen Intensity Mapping Experiment

    NASA Astrophysics Data System (ADS)

    Hincks, A. D.; Shaw, J. R.; Chime Collaboration

    2015-09-01

    The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is an ambitious new radio telescope project for measuring cosmic expansion and investigating dark energy. Keeping good records of both physical configuration of its 1280 antennas and their analogue signal chains as well as the ˜100 TB of data produced daily from its correlator will be essential to the success of CHIME. In these proceedings we describe the database-driven software we have developed to manage this complexity.

  10. Spectroscopic Low Coherence Interferometry

    NASA Astrophysics Data System (ADS)

    Bosschaart, Nienke; van Leeuwen, T. G.; Aalders, Maurice C.; Hermann, Boris; Drexler, Wolfgang; Faber, Dirk J.

    Low-coherence interferometry (LCI) allows high-resolution volumetric imaging of tissue morphology and provides localized optical properties that can be related to the physiological status of tissue. This chapter discusses the combination of spatial and spectroscopic information by means of spectroscopic OCT (sOCT) and low-coherence spectroscopy (LCS). We describe the theory behind these modalities for the assessment of spatially resolved optical absorption and (back)scattering coefficient spectra. These spectra can be used for the highly localized quantification of chromophore concentrations and assessment of tissue organization on (sub)cellular scales. This leads to a wealth of potential clinical applications, ranging from neonatology for the determination of billibrubin concentrations, to oncology for the optical assessment of the aggressiveness of a cancerous lesion.

  11. Neutrino Oscillations at the Intensity Frontier: The NOvA Experiment

    NASA Astrophysics Data System (ADS)

    Hatzikoutelis, Athanasios

    2013-02-01

    The "NuMI Off-Axis electron-neutrino Appearance" (NOvA) is a second generation, long- baseline, neutrino oscillation, experiment. It is made of two detectors, a large Far detector (14 ktons) and a similar Near detector (222 tons), both made of mostly active scintillator and separated by 810 km. Along with the 700 kW NuMI-beam upgrade (a prelude to the Intensity Frontier), it will be the leading neutrino experiment at Fermilab. In the wake of the recent measurement of the θ13 mixing angle, NOvA is positioned to see evidence of the neutrino mass hierarchy, possibly to resolve the θ23 octant ambiguity, and begin the study of the CP violation at the lepton sector. The experiment is under construction. The design and potential of this experiment is presented here along with the current status.

  12. Optical Long Baseline Interferometry News

    NASA Astrophysics Data System (ADS)

    Lawson, P. R.; Malbet, F.

    2005-12-01

    The Optical Long Baseline Interferometry News is a website and forum for scientists, engineers, and students who share an interest in long baseline stellar interferometry. It was established in 1995 and is the focus of activity of the IAU Working Group on Optical/Infrared Interferometry. Here you will find links to projects devoted to stellar interferometry, news items, recent papers and preprints, and resources for further research. The email news forum was established in 2001 to complement the website and to facilitate exchanges and collaborations. The forum includes an email exploder and an archived list of discussions. You are invited to explore the forum and website at http://olbin.jpl.nasa.gov. Work by PRL was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  13. The Prospects of SAS Interferometry for Detection and Classification (SAS Interferometrie voor Detectie en Classificatie)

    DTIC Science & Technology

    2008-10-01

    zal interferometrie toegepast gaan worden voor detectie en classificatie van begraven objecten. zoals explosieven Op dit gebied /al een experiment...uitgevoerd gaan worden voor het detecteren van in modder wegge- zakte explosieven. waarbij de in dit project ontwikkelde processing toegepast /.al... gaan worden PROGRAMMA PROJECT Program mabegeleider Project begeleider LTZ1 drs. R.P.A. Dekeling, DMO/OT LTZ1 drs. R.P.A. Dekeling, DMO/OT

  14. Infrasonic interferometry of stratospherically refracted microbaroms--a numerical study.

    PubMed

    Fricke, Julius T; El Allouche, Nihed; Simons, Dick G; Ruigrok, Elmer N; Wapenaar, Kees; Evers, Läslo G

    2013-10-01

    The atmospheric wind and temperature can be estimated through the traveltimes of infrasound between pairs of receivers. The traveltimes can be obtained by infrasonic interferometry. In this study, the theory of infrasonic interferometry is verified and applied to modeled stratospherically refracted waves. Synthetic barograms are generated using a raytracing model and taking into account atmospheric attenuation, geometrical spreading, and phase shifts due to caustics. Two types of source wavelets are implemented for the experiments: blast waves and microbaroms. In both numerical experiments, the traveltimes between the receivers are accurately retrieved by applying interferometry to the synthetic barograms. It is shown that microbaroms can be used in practice to obtain the traveltimes of infrasound through the stratosphere, which forms the basis for retrieving the wind and temperature profiles.

  15. Patient and Family Experience: A Comparison of Intensive Care and Overall Hospitalization.

    PubMed

    Lah, Soowhan; Wilson, Emily L; Rozenblum, Ronen; Hirshberg, Eliotte L; Hopkins, Ramona O; Orme, James; Brown, Samuel M

    2017-05-01

    The Hospital Consumer Assessment of Healthcare Providers and Systems survey is the most commonly used instrument for measuring patients' perceptions of the quality of inpatient care. To determine if the hospital survey can also be used to measure patients' experience of intensive care as indicated by scores on a parallel questionnaire, the Patient Perception of Quality. Scores on both instruments of all adult patients admitted to an intensive care unit from 2007 through 2012 were analyzed. A total of 1766 matching pairs of hospital and critical care surveys were identified. Patients' ratings of the overall hospital and critical care experiences had low correlation: r = 0.32 (95% CI, 0.28-0.37). Using the standard reporting convention, 77% of the participants rated the hospital as 9 or 10 on a 10-point scale, and 65% rated the intensive care unit as 5 on a 5-point scale. Although the hospital survey was always completed by the patient, the critical care survey was completed by a patient's family member or friend in 76% of cases and by the patient in 24%. Patient-completed critical care surveys had more correlation with hospital surveys (r = 0.45) than did critical care surveys completed by family members (r = 0.30), but the overall correlation remained modest. Scores on the hospital survey were at best modestly associated with scores on the critical care survey and did not reflect the specific experiences of patients and patients' families in the intensive care unit. ©2017 American Association of Critical-Care Nurses.

  16. The acute psychobiological impact of the intensive care experience on relatives

    PubMed Central

    Turner-Cobb, J.M.; Smith, P.C.; Ramchandani, P.; Begen, F.M.; Padkin, A.

    2016-01-01

    There is a growing awareness amongst critical care practitioners that the impact of intensive care medicine extends beyond the patient to include the psychological impact on close family members. Several studies have addressed the needs of relatives within the intensive care context but the psychobiological impact of the experience has largely been ignored. Such impact is important in respect to health and well-being of the relative, with potential to influence patient recovery. The current feasibility study aimed to examine the acute psychobiological impact of the intensive care experience on relatives. Using a mixed methods approach, quantitative and qualitative data were collected simultaneously. Six relatives of patients admitted to the intensive care unit (ICU) of a District General Hospital, were assessed within 48 h of admission. Qualitative data were provided from semi-structured interviews analysed using interpretative phenomenological analysis. Quantitative data were collected using a range of standardised self-report questionnaires measuring coping responses, emotion, trauma symptoms and social support, and through sampling of diurnal salivary cortisol as a biomarker of stress. Four themes were identified from interview: the ICU environment, emotional responses, family relationships and support. Questionnaires identified high levels of anxiety, depression and trauma symptoms; the most commonly utilised coping techniques were acceptance, seeking support through advice and information, and substance use. Social support emerged as a key factor with focused inner circle support relating to family and ICU staff. Depressed mood and avoidance were linked to greater mean cortisol levels across the day. Greater social network and coping via self-distraction were related to lower evening cortisol, indicating them as protective factors in the ICU context. The experience of ICU has a psychological and physiological impact on relatives, suggesting the importance of

  17. Simulations and experiments of intense ion beam current density compression in space and timea)

    NASA Astrophysics Data System (ADS)

    Sefkow, A. B.; Davidson, R. C.; Gilson, E. P.; Kaganovich, I. D.; Anders, A.; Coleman, J. E.; Leitner, M.; Lidia, S. M.; Roy, P. K.; Seidl, P. A.; Waldron, W. L.; Yu, S. S.; Welch, D. R.

    2009-05-01

    The Heavy Ion Fusion Science Virtual National Laboratory has achieved 60-fold longitudinal pulse compression of ion beams on the Neutralized Drift Compression Experiment (NDCX) [P. K. Roy et al., Phys. Rev. Lett. 95, 234801 (2005)]. To focus a space-charge-dominated charge bunch to sufficiently high intensities for ion-beam-heated warm dense matter and inertial fusion energy studies, simultaneous transverse and longitudinal compression to a coincident focal plane is required. Optimizing the compression under the appropriate constraints can deliver higher intensity per unit length of accelerator to the target, thereby facilitating the creation of more compact and cost-effective ion beam drivers. The experiments utilized a drift region filled with high-density plasma in order to neutralize the space charge and current of an ˜300 keV K+ beam and have separately achieved transverse and longitudinal focusing to a radius <2 mm and pulse duration <5 ns, respectively. Simulation predictions and recent experiments demonstrate that a strong solenoid (Bz<100 kG) placed near the end of the drift region can transversely focus the beam to the longitudinal focal plane. This paper reports on simulation predictions and experimental progress toward realizing simultaneous transverse and longitudinal charge bunch focusing. The proposed NDCX-II facility would capitalize on the insights gained from NDCX simulations and measurements in order to provide a higher-energy (>2 MeV) ion beam user-facility for warm dense matter and inertial fusion energy-relevant target physics experiments.

  18. Short-term, intensive neurodevelopmental treatment program experiences of parents and their children with disabilities.

    PubMed

    Evans-Rogers, Debbie L; Sweeney, Jane K; Holden-Huchton, Patricia; Mullens, Pamela A

    2015-01-01

    Parents' perspectives on intervention and functional changes in children were investigated following an intensive neurodevelopmental treatment (NDT) program of 1 to 2 weeks (5 consecutive days per week; 2-4 h/d). Thirteen parents and their children (aged 1-17 years) with neuromotor conditions participated in a short-term, intensive program conducted by NDT certified pediatric therapists. A mixed-method design was used: a qualitative phenomenological approach of inquiry for parent perspectives and a pre/posttest quasi-experimental design for weekly intervention changes using Goal Attainment Scaling and the Canadian Occupational Performance Measure. Through interviews, parents reported positive experiences with the intensive NDT program. Child participants demonstrated significant improvements in Goal Attainment Scaling (P < .001) and Canadian Occupational Performance Measure (P < .001) scores pre- to postintervention. A short-term, intensive NDT program was perceived by parents as beneficial and supported functional improvements. Valued were expert, compassionate therapists; collaboration; objective goals; home programming; and individualized intervention. Scheduling, financial support, and fatigue were difficulties.

  19. [Psychological experience of health care professionals in intensive care unit: a qualitative and exploratory study].

    PubMed

    Chahraoui, K; Bioy, A; Cras, E; Gilles, F; Laurent, A; Valache, B; Quenot, J-P

    2011-04-01

    Study the subjective and emotional experience of health care professionals in intensive care unit in front of sources of professional stress connected to the emergency and to the gravity of the pathologies of hospitalized patients. A clinical interview was proposed to health care professionals of an intensive care unit during which they had to develop their personal feeling about the organization of the work and their management of the most stressful emotional situations. All interviews were entirely recorded and rewritten. Then, they were the object of a procedure of coding and a thematic analysis was detailed with the consensus of several individuals. Eighteen professionals agreed to participate in this research. The analysis of these clinical interviews showed a strong feeling of pressure in works as being mainly focused on the necessity of control the procedures and the technical means involved in intensive care unit and in the strong emotional load due to deaths of patients and to the pain of families. The management of the death and its conditions appears as a major and central difficulty. The discussion approaches the question of the feeling of pressure at works and its various items by underlining the interpersonal variations of these experiences, then the question of the emotional adaptation through the individual and collective defensive strategies organized to cope with these various situations. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  20. Neutron interferometry with cold stage

    NASA Astrophysics Data System (ADS)

    Mineeva, Taisiya; Arif, M.; Huber, M. G.; Shahi, C. B.; Clark, C. W.; Cory, D. G.; Nsofini, J.; Sarenac, D.; Pushin, D. A.

    Neutron interferometry (NI) is amongst the most precise methods for characterizing neutron interactions by measuring the relative difference between two neutron paths, one of which contains a sample-of-interest. Because neutrons carry magnetic moment and are deeply penetrating, they are excellent probes to investigate properties of magnetic materials. The advantage of NI is its unique sensitivity which allows to directly measure magnetic and structural transitions in materials. Up to now NI has been sparingly used in material research due to its sensitivity to environmental noise. However, recent successes in implementing Quantum Error Correction principles lead to an improved NI design making it robust against mechanical vibrations. Following these advances, a new user facility at the National Institute for Standards and Technology was built to study condensed matter applications, biology and quantum physics. Incorporating cold sample stage inside NI is the first of its kind experiment which can be carried out on large range of temperatures down to 4K. Upon successful realization, it will open new frontiers to characterize magnetic domains, phase transitions and spin properties in a variety of materials such as, for example, iron-based superconductors and spintronic materials. Supported in part by CERC, CIFAR, NSERC and CREATE.

  1. The Parental Experience of Having an Infant in the Newborn Intensive Care Unit

    PubMed Central

    Obeidat, Hala M.; Bond, Elaine A.; Callister, Lynn Clark

    2009-01-01

    The purpose of this systematic review was to explore and describe the experience of parents with an infant in the newborn intensive care unit (NICU). A literature search covering the period 1998–2008 was conducted. Fourteen articles reporting qualitative studies describing parental experiences and meeting the inclusion criteria were evaluated and themes were identified. Findings revealed that parents with an infant in the NICU experience depression, anxiety, stress, and loss of control, and they vacillate between feelings of inclusion and exclusion related to the provision of health care to their neonate. Nursing interventions that promote positive psychosocial outcomes are needed to decrease parental feelings of stress, anxiety, and loss of control. Interventions need to focus on family-centered and developmentally supportive care. PMID:20514124

  2. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus

    NASA Astrophysics Data System (ADS)

    Kim, YooSung; Shi, Yue-Jiang; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Oh, Soo-Ghee; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-11-01

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hα and Hβ radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  3. [Care of mothers of newborns in intensive care units: experiences, feelings and expectations of the mothers].

    PubMed

    Belli, M A

    1995-08-01

    The purpose of the study was to examine the experiences, feelings and expectation of mothers of high risk newborns. The population was a group of 20 mothers of high risk newborns of three hospitals in the City of São Paulo. Interview with the mothers was the method of data collection containing opened and structured questions. It was verified that most of the mothers had none or only a little interaction with the newborn after delivery; the eye contact was the most referred during the staying of the newborn in the Intensive Care Unity; all of them demonstrated interest in participating in the care of the newborn and expressed the need of information concerning to the health status of the newborn, the Intensive Care Unity environment and the hospital team. Several were the feelings expressed and the motives that indicated the needs of the mothers.

  4. Bremsstrahlung Dose Yield for High-Intensity Short-Pulse Laser–Solid Experiments

    DOE PAGES

    Liang, Taiee; Bauer, Johannes M.; Liu, James C.; ...

    2016-12-01

    A bremsstrahlung source term has been developed by the Radiation Protection (RP) group at SLAC National Accelerator Laboratory for high-intensity short-pulse laser–solid experiments between 1017 and 1022 W cm–2. This source term couples the particle-in-cell plasma code EPOCH and the radiation transport code FLUKA to estimate the bremsstrahlung dose yield from laser–solid interactions. EPOCH characterizes the energy distribution, angular distribution, and laser-to-electron conversion efficiency of the hot electrons from laser–solid interactions, and FLUKA utilizes this hot electron source term to calculate a bremsstrahlung dose yield (mSv per J of laser energy on target). The goal of this paper is tomore » provide RP guidelines and hazard analysis for high-intensity laser facilities. In conclusion, a comparison of the calculated bremsstrahlung dose yields to radiation measurement data is also made.« less

  5. Bremsstrahlung Dose Yield for High-Intensity Short-Pulse Laser–Solid Experiments

    SciTech Connect

    Liang, Taiee; Bauer, Johannes M.; Liu, James C.; Rokni, Sayed H.

    2016-12-01

    A bremsstrahlung source term has been developed by the Radiation Protection (RP) group at SLAC National Accelerator Laboratory for high-intensity short-pulse laser–solid experiments between 1017 and 1022 W cm–2. This source term couples the particle-in-cell plasma code EPOCH and the radiation transport code FLUKA to estimate the bremsstrahlung dose yield from laser–solid interactions. EPOCH characterizes the energy distribution, angular distribution, and laser-to-electron conversion efficiency of the hot electrons from laser–solid interactions, and FLUKA utilizes this hot electron source term to calculate a bremsstrahlung dose yield (mSv per J of laser energy on target). The goal of this paper is to provide RP guidelines and hazard analysis for high-intensity laser facilities. In conclusion, a comparison of the calculated bremsstrahlung dose yields to radiation measurement data is also made.

  6. The intensity reduction of ground shadow To deliver better viewing experiences of soccer videos

    NASA Astrophysics Data System (ADS)

    Ko, Jaeseung; Lee, Jaeho; Kim, Changick; Bhaskaran, Vasudev

    2007-09-01

    In this paper, we present a method for reducing the intensity of shadows cast on the ground in outdoor sports videos to provide TV viewers with a better viewing experience. In the case of soccer videos taken by a long-shot camera technique, it is difficult for viewers to discriminate the tiny objects (i.e., soccer ball and player) from the ground shadows. The algorithm proposed in this paper comprises three modules, such as long-shot detection, shadow region extraction and shadow intensity reduction. We detect the shadow region on the ground by using the relationship between Y and U values in YUV color space and then reduce the shadow components depending on the strength of the shadows. Experimental results show that the proposed scheme offers useful tools to provide a more comfortable viewing environment and is amenable to real-time performance even in a software based implementation.

  7. Paul Trap Simulator Experiment to Model Intense Beam Propagation in Alternating-gradient Transport Systems

    SciTech Connect

    Erik P. Gilson; Ronald C. Davidson; Philip C. Efthimion; Richard Majeski

    2004-01-29

    The results presented here demonstrate that the Paul Trap Simulator Experiment (PTSX) simulates the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient (AG) transport systems by making use of the similarity between the transverse dynamics of particles in the two systems. Plasmas have been trapped that correspond to normalized intensity parameters s = wp2 (0)/2wq2 * 0.8, where wp(r) is the plasmas frequency and wq is the average transverse focusing frequency in the smooth-focusing approximation. The measured root-mean-squared (RMS) radius of the beam is consistent with a model, equally applicable to both PTSX and AG systems that balances the average inward confining force against the outward pressure-gradient and space-charge forces. The PTSX device confines one-component cesium ion plasmas for hundreds of milliseconds, which is equivalent to over 10 km of beam propagation.

  8. Plant diversity enhances moth diversity in an intensive forest management experiment.

    PubMed

    Root, Heather T; Verschuyl, Jake; Stokely, Thomas; Hammond, Paul; Scherr, Melissa A; Betts, Matthew G

    2017-01-01

    Intensive forest management (IFM) promises to help satisfy increasing global demand for wood but may come at the cost of local reductions to forest biodiversity. IFM often reduces early seral plant diversity as a result of efforts to eliminate plant competition with crop trees. If diversity is a function of bottom-up drivers, theory predicts that specialists at lower trophic levels (e.g., insect herbivores) should be particularly sensitive to reductions in plant diversity. We conducted a stand-level experiment to test bottom-up controls on moth community structure, as mediated by degrees of forest management intensity. Using a dataset of 12,003 moths representing 316 moth species, moth richness decreased only slightly, if at all, as herbicide intensity increased (P = 0.062); the moderate treatment, which is most commonly applied in the northwestern USA, was estimated to have 4.72 (±2.14 SE, P = 0.039) fewer species than the control. Structural equation modeling revealed strong support for an effect of herbicide on plant abundance, which influenced plant species richness and subsequently moth species richness. Moth species richness was associated with plant species richness and followed a power law function (z = 0.42, P = 0.006), which is surprisingly consistent with a recent large-scale experiment in agricultural systems, and provides support for bottom-up drivers of moth community structure. Moth abundance was not influenced by the direct effects of silvicultural herbicide treatments. Site-level effects and variation in pre-harvest vegetation communities resulted in residual broadleaf and herbaceous vegetation in even the most intensive treatment. Even at low densities, these residual deciduous and herbaceous plants supported higher than expected moth abundance and richness. We conclude that forest management practices that retain early seral vegetation diversity are the most likely to conserve moth communities. © 2016 by the Ecological Society of

  9. Simulator for the Parity-Violating Deep Inelastic Scattering experiment in the Solenoidal Large Intensity Detector

    NASA Astrophysics Data System (ADS)

    Anderson, Jack; Hall A SoLID Collaboration

    2013-10-01

    The Solenoid Large Intensity Detector (SoLID) particle detector is the main detector that will be used for high energy particle experiments in Hall A that will be used with the 12 GeV electron beam at the Jefferson Lab. SoLID geometries were writen to be implemented in Geant4 using openGL as the visualization tool. This will allow us to test how the calorimeter, a specific yet integral part of the SoLID detector, detects the particles that result from electron beams colliding with targets. The goal is to simulate the approved experiments for the SoLID detector, starting with the Parity-Violating Deep Inelastic Scattering (PVDIS) experiment. This will provide critical information regarding the effectiveness of the calorimeter's design for such experiments. The expectation is that a Shashlik calorimeter will prove effective for the experiments approved for the SoLID detector. The ideal number of layers, or types of material for said layers, is an aspect of the calorimeter that will require testing through the simulations.The geometry files allow an easily-packaged program that can be shared amongst any collaborators interested in the SoLID experiments. NSF Grant No. 714001.

  10. Shot-Peening Intensities VS. Eddy Current Signals as Seen in Iterative Treatment-Measurement Experiment

    NASA Astrophysics Data System (ADS)

    Nakagawa, N.; Frishman, A. M.; Shen, Y.; Lo, C. C. H.

    2009-03-01

    We report on progress in a swept high frequency eddy current (SHFEC) technique for characterization of surface residual stress on shot-peened superalloy surfaces. Our aim here is to demonstrate the sensitivity of our measurement for practical shot peening intensities, i.e. at 4˜6 A. First, we present our improved probe and instrumentation being sufficiently sensitive to resolve the surface conditions at these low Almen intensities, where our earlier measurements encountered noise problems. The previous coil was also larger (18 mm in diameter) than desirable. Our new probe integrates smaller coils (12 mm in diameter, forming an AC bridge) and on-board electronics on a common printed circuit board, mutually connected at the shortest possible distance. The operational-amplifier-based electronics acts as impedance buffers, and maintains the cabling impedance at the characteristic 50 Ω between the probe board and the instruments. We have thus reduced the instrumentation noises. Second, we present the result of an iterative treatment-measurement experiment, performed on a 2"-by-3" Inconel 718 block specimen, initially polished to a mirror finish. After an initial baseline SHFEC measurement, we performed shot peening, an Almen strip deflection measurement, and a SHFEC measurement as one iteration cycle, and repeated the cycles multiple times at predetermined intervals. We will show the resulting SHFEC signals (i.e. lift-off normalized vertical-component signals) plotted against the Almen intensities. We then draw several conclusions from the experimental data, including a) the SHFEC signals increase monotonically in correlation with the Almen intensity increase, and b) the SHFEC signals exhibit sufficient deviations to resolve 4˜6 A intensities, while c) the SHFEC signals indicate saturation of the Inconel 718 response against peening, but the saturation occurs later in the iteration than indicated by the A-series Almen strip.

  11. Atom Interferometry in a Warm Vapor

    DOE PAGES

    Biedermann, G. W.; McGuinness, H. J.; Rakholia, A. V.; ...

    2017-04-17

    Here, we demonstrate matter-wave interference in a warm vapor of rubidium atoms. Established approaches to light-pulse atom interferometry rely on laser cooling to concentrate a large ensemble of atoms into a velocity class resonant with the atom optical light pulse. In our experiment, we show that clear interference signals may be obtained without laser cooling. This effect relies on the Doppler selectivity of the atom interferometer resonance. Lastly, this interferometer may be configured to measure accelerations, and we demonstrate that multiple interferometers may be operated simultaneously by addressing multiple velocity classes.

  12. Holographic diversity interferometry for optical storage.

    PubMed

    Okamoto, Atsushi; Kunori, Keisuke; Takabayashi, Masanori; Tomita, Akihisa; Sato, Kunihiro

    2011-07-04

    This study proposes holographic diversity interferometry (HDI), a system that combines information from spatially dispersed plural image sensors to reconstruct complex amplitude distributions of light signals. HDI can be used to generate four holographic interference fringes having different phases, thus enabling optical phase detection in a single measurement. Unlike conventional phase-shifting digital holography, this system does not require piezoelectric elements and phase shift arrays. In order to confirm the effectiveness of HDI, we generated optical signals having multilevel phases and amplitudes by using two SLMs and performed an experiment for detection and demodulation with HDI.

  13. Atomic interferometry test of dark energy

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Davis, Anne-Christine

    2016-11-01

    Atomic interferometry can be used to probe dark energy models coupled to matter. We consider the constraints coming from recent experimental results on models generalizing the inverse power law chameleons such as f (R ) gravity in the large curvature regime, the environmentally dependent dilaton and symmetrons. Using the tomographic description of these models, we find that only symmetrons with masses smaller than the dark energy scale can be efficiently tested. In this regime, the resulting constraints complement the bounds from the Eötwash experiment and exclude small values of the symmetron self-coupling.

  14. Probing dark energy with atom interferometry

    SciTech Connect

    Burrage, Clare; Copeland, Edmund J.; Hinds, E.A. E-mail: Edmund.Copeland@nottingham.ac.uk

    2015-03-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  15. Probing dark energy with atom interferometry

    NASA Astrophysics Data System (ADS)

    Burrage, Clare; Copeland, Edmund J.; Hinds, E. A.

    2015-03-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  16. Fruitful or futile: intensive care nurses' experiences and perceptions of medical futility.

    PubMed

    Heland, Melodie

    2006-02-01

    The study sought to investigate the perceptions and experiences of nurses practising in adult intensive care units (ICUs) with regard to medical futility. A qualitative exploratory descriptive design was used, providing a framework which enabled information to be gathered on a relatively undefined phenomena. Data were gathered via semi-structured interviews with seven intensive care nurses. Findings concluded that there is no 'one size fits all' definition of medical futility. To arrive at the decision whether treatment is futile, participants want to understand patients' views on treatment limitation. In some ICUs, 'the decision' about whether to cease or continue treatment is unilaterally made by medical staff, raising concerns about value laden judgement. Nurses experience frustration with having to administer treatment with which they do not agree and may actually leave intensive care nursing because of their moral conflict. There are opportunities for nurses to have input into 'the decision', but they must have a cogent and articulate approach to be heard. Once treatment is deemed to be futile, nurses play a key role in treatment withdrawal and can have a significant impact on the patient and family experience if they manage the situation well; this nursing role in medically futile situations and treatment withdrawal is detailed. 'Medical futility' is not easily defined. Understanding patients' views about treatment limitation is important in deciding whether treatment is medically futile. To do this, an inclusive decision making process should be developed by ICUs which incorporates nursing and family input. Experienced ICU nurses can have a significant impact on the management of futile cases; they need to share their understanding of the processes surrounding medical futility and assist junior nurses in negotiating the difficult challenges encountered in decision making and treatment withdrawal.

  17. Progress towards photon-counting infrared arrays for interferometry

    NASA Astrophysics Data System (ADS)

    Buscher, David F.; Seneta, Eugene B.; Sun, Xiaowei; Young, John S.; Finger, Gert

    2016-08-01

    The advent of low-dark-current eAPD arrays in the near infrared ushers in the possibility for photon-counting, high quantum efficiency detectors at these wavelengths. Such detectors would revolutionise the sensitivity of interferometry because near-infrared wavelengths are at the "sweet spot" between the corrupting effects of atmospheric seeing at shorter wavelengths and thermal noise at longer wavelengths. We report on laboratory experiments with cooled Selex Saphira detectors aimed at demonstrating photon-counting performance with these devices by exploiting enhanced avalanche gain and multiple non-destructive readouts. We explain the optimum modes for employing these detectors in interferometry.

  18. Absolute distance measurement based on multiple self-mixing interferometry

    NASA Astrophysics Data System (ADS)

    Duan, Zhiwei; Yu, Yangyang; Gao, Bingkun; Jiang, Chunlei

    2017-04-01

    To improve the precision of distance measurement using laser Self-Mixing Interferometry (SMI) and compute short distance, we propose a method of Multiple Self-Mixing Interferometry (MSMI) that is modulated with a triangular wave. The principle of this method has been described in this paper. Experiments at different distances and amplitudes of modulation current are based on the proposed method. Low-priced and easily operated experimental devices are built. Experimental results show that a resolution of 2.7 mm can be achieved for absolute distance ranging from 2.2 to 23 cm.

  19. Geometric time delay interferometry

    SciTech Connect

    Vallisneri, Michele

    2005-08-15

    The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using time delay interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the interspacecraft phase measurements. The TDI observables of the Michelson and Sagnac types have been interpreted physically as the virtual measurements of a synthesized interferometer. In this paper, I present Geometric TDI, a new and intuitive approach to extend this interpretation to all TDI observables. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of second-generation TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent arm lengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have improved high-frequency gravitational-wave sensitivity in realistic noise conditions (because they have fewer nulls in the gravitational-wave and noise response functions), and are less susceptible to instrumental gaps and glitches (because their component phase measurements span shorter time periods)

  20. Experimental research of dynamic stitching interferometry for large plano optics

    NASA Astrophysics Data System (ADS)

    Wu, Xin; Qi, Te; Yu, Yingjie

    2017-02-01

    Stitching interferometry is an effective method to extend the measurement range of commercial interferometer. It has been applied in the laboratorial environment, but rarely in workshop. In order to improve the testing efficiency in workshop, stitching interferometry could be combined with machine tool and implement in-situ testing. A dynamic stitching interferometer system is established in this paper, which contains dynamic interferometry, precision motion control and advanced stitching algorithm. This system has been prepared for the in-situ testing of large plano optics. One example optical flat with size 200mm×300mm was used to verify the feasibility and accuracy of this system. Many repetitive experiments have been proved the well reliability of the system and method.

  1. A Novel Femtosecond-gated, High-resolution, Frequency-shifted Shearing Interferometry Technique for Probing Pre-plasma Expansion in Ultra-intense Laser Experiments

    DTIC Science & Technology

    2014-07-17

    the broadband 800 nm seed pulse of the probe beam is optically filtered using Schott RG850 glass , moving the central wavelength to 840 nm by prefer...via a β-barium borate crystal (AR/AR coated, 300 μm thick, Type I). During imaging, two optical notch filters (Semrock FF01-420/10-25; 10 nm bandwidth

  2. How to Test Atom and Neutron Neutrality with Atom Interferometry

    SciTech Connect

    Arvanitaki, Asimina; Dimopoulos, Savas; Geraci, Andrew A.; Hogan, Jason; Kasevich, Mark

    2008-03-28

    We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{sup -28}e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{sup -28}e, 7 orders of magnitude below current bounds.

  3. Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry

    SciTech Connect

    Gutierrez, Thomas D.

    2006-03-02

    Two-particle interferometry, a second-order interferenceeffect, is explored as another possible tool to distinguish betweenmassive Dirac and Majorana neutrinos. A simple theoretical framework isdiscussed in the context of several gedanken experiments. The method canin principle provide both the mass scale and the quantum nature of theneutrino for a certain class of incoherent left-handed sourcecurrents.

  4. Testing Atom and Neutron Neutrality with Atom Interferometry

    SciTech Connect

    Arvanitaki, Asimina; Dimopoulos, Savas; Geraci, Andrew A.; Hogan, Jason; Kasevich, Mark; /Stanford U., Phys. Dept.

    2008-01-07

    We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{sup -28} e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{sup 28} e, 7 orders of magnitude below current bounds.

  5. Intensive care nurses' experiences and perceptions of delirium and delirium care.

    PubMed

    Zamoscik, Katarzyna; Godbold, Rosemary; Freeman, Pauline

    2017-06-01

    To explore nurses' experiences and perceptions of delirium, managing delirious patients, and screening for delirium, five years after introduction of the Confusion Assessment Method for Intensive Care into standard practice. Twelve nurses from a medical-surgical intensive care unit in a large teaching hospital attended two focus group sessions. The collected qualitative data was thematically analysed using Braun and Clarke's framework (2006). The analysis identified seven themes: (1) Delirium as a Secondary Matter (2) Unpleasant Nature of Delirium (3) Scepticism About Delirium Assessment (4) Distrust in Delirium Management (5) Value of Communication (6) Non-pharmacological Therapy (7) Need for Reviewed Delirium Policy. Nurses described perceiving delirium as a low priority matter and linked it to work culture within the intensive care specialty. Simultaneously, they expressed their readiness to challenge this culture and to promote the notion of providing high-quality delirium care. Nurses discussed their frustrations related to lack of confidence in assessing delirium, as well as lack of effective therapies in managing this group of patients. They declared their appreciation for non-pharmacological interventions in treatment of delirium, suggested improvements to current delirium approach and proposed introducing psychological support for nurses dealing with delirious patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The SPIRAL2 Project and experiments with high-intensity rare isotope beams

    NASA Astrophysics Data System (ADS)

    Lewitowicz, Marek

    2011-09-01

    The SPIRAL2 facility at GANIL, which entered recently in the construction phase consists of a new superconducting linear accelerator delivering high intensity, up to 40 MeV, light (proton, deuteron, 3-4He) beams as well as a large variety of 14.5 MeV/nucleon heavy-ion beams and the associated Rare Isotope Beam facility. Using a dedicated converter and the 5 mA deuteron beam, a neutron-induced fission rate is expected to approach 1014 fissions/s for high-density UCx target. The energies of accelerated RIBs will reach 5-10 MeV/nucleon for fission fragments and 20 MeV/nucleon for neutron-deficient nuclei. The physics case of SPIRAL2 is based on the use of high intensity RIBs & stable-ion beams and on possibilities to perform several experiments simultaneously. A use of these beams at a new low-energy ISOL facility (DESIR) and their acceleration to several MeV/nucleon will open new possibilities in nuclear structure physics, nuclear astrophysics and reaction dynamics studies. The high intensities (up to 1011pps) and a high cost of RIBs impose a use of the most efficient and innovative detection systems like ACTAR, FAZIA, GASPARD, HELIOS, NEDA, PARIS and a new separator/spectrometer S3.

  7. Transition from neonatal intensive care unit to special care nurseries: experiences of parents and nurses.

    PubMed

    Helder, Onno K; Verweij, Jos C M; van Staa, AnneLoes

    2012-05-01

    To explore parents' and nurses' experiences with the transition of infants from the neonatal intensive care unit to a special care nursery. Qualitative explorative study in two phases. Level IIID neonatal intensive care unit in a university hospital and special care nurseries (level II) in five community hospitals in the Netherlands. Twenty-one pairs of parents and 18 critical care nurses. Semistructured interviews were used. Thematic analysis and comparison of themes across participants were performed. Trust was a central theme for parents. Three subthemes, related to the chronological stages of transition, were identified: gaining trust; betrayal of trust; and rebuilding confidence. Trust was associated with five other themes: professional attitude; information management; coordination of transfer; different environments; and parent participation. Although nurses at an early stage repeatedly mentioned a possible transition to community hospitals, the actual announcement took many parents by surprise. Parents felt excluded during the actual transfer and most questioned its necessity. In the special care nursery, parents found it difficult to adjust to new routines and to gain trust in new caregivers, but eventually their worries dissolved. In contrast to neonatal intensive care unit nurses, special care nursery nurses quite understood the impact of transition on parents. Both parents and nurses considered present transitional arrangements to be inadequate. Nurses should provide more effective discharge planning and transitional care. A positive labeling of the transition as a first step to home discharge for the newborn seems appropriate. Parents need to be better-informed and should be involved in the planning process.

  8. Simulation of Experiments Generating Collisionless Shocks With Intense Lasers Using the CRASH Code

    NASA Astrophysics Data System (ADS)

    Grosskopf, M. J.; Drake, R. P.; Kuranz, C. C.; Rutter, E. M.; Park, H. S.; Kugland, N. L.; Pollaine, S.; Ross, J. S.; Remington, B. A.; Ryutov, D.; Spitkovsky, A.; Gargate, L.; Gregori, G.; Bell, A.; Murphy, C.; Sakawa, Y.; Kuramitsu, Y.; Takabe, H.; Froula, D. H.; Fiksel, G.; Miniati, F.; Koenig, M.; Ravasio, A.; Liang, E.; Woosley, N.

    2011-10-01

    Collisionless shocks, shocks generated by plasma wave interactions in regions where the collisional mean-free-path for particles is long compared to the length scale for shock interaction, are found ubiquitously in astrophysics. Experiments to investigate collisionless shocks in a laboratory-scale system are being carried out on intense lasers; measuring the density, temperature, magnetic field, and velocity of counter-streaming flows generated by laser ablation. This poster reports hydrodynamic simulations modeling the ablative flow of plasma generated in order to assess potential designs and infer properties of collected data from previous single foil experiments. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52-08NA28616.

  9. Stellar Interferometry from the Ground and Space

    NASA Technical Reports Server (NTRS)

    Danchi, William C.; Oegerle, William (Technical Monitor)

    2002-01-01

    Stellar Interferometry began more than 80 years ago with the pioneering measurement of the diameter of Betelqueuse by Michelson and Pease using a 20 foot beam mounted at the top of the 10011 Hooker telescope at Mt. Wilson. Essentially no other work was done in this field until the 1960's when Hanbury-Brown and his colleagues developed and used the Intensity Interferometer at Narrabri, Australia to measure the diameters of a number of important hot stars. The modern period of Stellar Interferometry really began in the 1970's with the successes of 3 or 4 small research groups in the US and Europe, and scientific and technical progress in the field has been outstanding, particularly in the last decade. This has lead to the development of two major ground based facilities: NASA's own Keck Interferometer and ESO's Very Large Telescope Interferometer, and a number of space interferometers such as the Space Interferometer Mission (SIM), and the Terrestrial Planet Finder (TPF), among others. I will review the principles, history, and scientific progress in the field both on the ground and in space, and I will discuss a mission concept under development here at NASA Goddard, the Fourier-Kelvin Stellar Interferometer, a near-term mid-infrared imaging interferometer, which can serve as a scientific and technical pre-cursor for some of the more ambitious concepts being discussed within the Astronomical and NASA communities.

  10. Physical restraint: experiences, attitudes and opinions of adult intensive care unit nurses.

    PubMed

    Freeman, Samantha; Hallett, Christine; McHugh, Gretl

    2016-03-01

    Patients within the adult intensive care unit have the potential to develop delirium and agitation. This can result in the patient displaying unwanted behaviours such as attempting to remove the medical devices to which they are attached. Some adult intensive care units within the UK are starting to adopt physical restraint as a method of managing unwanted behaviours. To determine the experiences, attitudes and opinions of adult intensive care nurses in relation to the application of physical restraint. Questionnaire survey. A postal questionnaire was distributed to all nurses (n = 192) within two purposefully selected large adult intensive care units in the UK. Data were collected between November 2012 and February 2013. The questionnaire was completed by 38·9% (n = 75) of the nurses contacted. All believed that physical restraint had a place, with the majority of the view that the reason for its application was to maintain patient safety. Some expressed discomfort about the use of physical restraint. Nurses were happy to discuss the use of restraint with families. There was a perceived need for training and support for nursing staff as well as the need for medical staff to support the decision-making process. Nurses require more support and evidence to base their decision-making upon. They require guidance from professional bodies as well as support from medical colleagues. The findings have limited generalizability as they can only be applied to the units accessed and the response rate was poor. Alternative approaches such as pain management, sleep promotion and the involvement of relatives need to be explored before physical restraint policy can be written. Further research is required into the safety of physical restraint, alternative methods of managing the risk of agitation and identifying predisposing factors to accidental device removal. © 2015 British Association of Critical Care Nurses.

  11. Family members' lived experiences of everyday life after intensive care treatment of a loved one: a phenomenological hermeneutical study.

    PubMed

    Frivold, Gro; Slettebø, Åshild; Dale, Bjørg

    2016-02-01

    To illuminate relatives' experiences of everyday life after a loved one's stay in an intensive care unit. Relatives of intensive care patients experience considerable stress that can have a long-lasting effect on their everyday lives. Relatives frequently report anxiety, depression and complicated grief as a result of their experiences in the intensive care unit. A qualitative design was chosen. Thirteen relatives were interviewed 3 months to 1 year after the discharge or death of an intensive care unit patient. A phenomenological hermeneutical method was used to explore family members' lived experiences upon returning home after their loved ones' stay in the intensive care unit. Two themes emerged from the analysis of the data: (1) changes in everyday life and emotional reactions, and (2) managing changes and need of support and follow-up from the ICU. Family members experience changes in emotions, roles and responsibilities after returning home. They must maintain control of themselves and adapt to the changes to face the future. They cope by using their personal resources and support from others. Some are in further need of follow-up from the intensive care unit staff. Nursing education could focus increasingly more on the significance of communication and personal support, which helps family members cope during patients' stay and experience a sense of personal strength when returning home. Further research should address how to identify and support those with special needs after the intensive care unit stay. © 2016 John Wiley & Sons Ltd.

  12. 100-Picometer Interferometry for EUVL

    SciTech Connect

    Sommargren, G E; Phillion, D W; Johnson, M A; Nguyen, N O; Barty, A; Snell, F J; Dillon, D R; Bradsher, L S

    2002-03-18

    Future extreme ultraviolet lithography (EWL) steppers will, in all likelihood, have six-mirror projection cameras. To operate at the diffraction limit over an acceptable depth of focus each aspheric mirror will have to be fabricated with an absolute figure accuracy approaching 100 pm rms. We are currently developing visible light interferometry to meet this need based on modifications of our present phase shifting diffraction interferometry (PSDI) methodology where we achieved an absolute accuracy of 250pm. The basic PSDI approach has been further simplified, using lensless imaging based on computational diffractive back-propagation, to eliminate auxiliary optics that typically limit measurement accuracy. Small remaining error sources, related to geometric positioning, CCD camera pixel spacing and laser wavelength, have been modeled and measured. Using these results we have estimated the total system error for measuring off-axis aspheric EUVL mirrors with this new approach to interferometry.

  13. Noise-assisted Ramsey interferometry

    NASA Astrophysics Data System (ADS)

    Dorner, U.

    2013-12-01

    I analyze a metrological strategy for improving the precision of frequency estimation via Ramsey interferometry with strings of atoms in the presence of correlated dephasing. This strategy does not employ entangled states but rather a product state which evolves into a stationary state under the influence of correlated dephasing. It is shown that by using this state an improvement in precision compared to standard Ramsey interferometry can be gained. This improvement is not an improvement in scaling; i.e., the estimation precision has the same scaling with the number of atoms as the standard quantum limit but gains an improvement proportional to the free evolution time in the Ramsey interferometer. Since a stationary state is used, this evolution time can be substantially larger than in standard Ramsey interferometry which is limited by the coherence time of the atoms.

  14. Future changes in daily snowfall intensity projected by large ensemble regional climate experiments

    NASA Astrophysics Data System (ADS)

    Kawase, H.

    2015-12-01

    We investigate the future changes in daily snowfall intensity in Japan analyzing the large ensemble regional climate experiments. Dynamical downscalings are conducted by Non-Hydrostatic Regional Climate Model (NHRCM) with 20 km from the global climate projections using Meteorological Research Institute-Atmospheric General Circulation Model (MRI-AGCM). Fifty ensemble experiments are performed in the present climate. For the future climate projections, 90 ensemble experiments are performed based on the six patterns of SST changes in the periods when 4 K rise in global-mean surface air temperature is projected. The accumulated snowfall in winter decreases in Japan except for the northern parts of Japan. Especially, the inland areas in the Sea of Japan side, which is famous for the heaviest snowfall region in the world, shows the remarkable decrease in snowfall in the future climate. The experiments also show increased number of days without snowfall and decreased number of days with weak snowfall due to significant warming in the most parts of Japan. On the other hand, the extreme daily snowfall, which occurs once ten years, would increase at higher elevations in the Sea of Japan side. This means that extreme daily snowfall in the present climate would occur more frequently in the future climate. The warmer atmosphere can contain more water vapor and warmer ocean can supply more water vapor to the low atmosphere. The surface air temperature at higher elevations is still lower than 0 degree Celsius, which could result in the increased extreme daily snowfall.

  15. Techniques in Broadband Interferometry

    SciTech Connect

    Erskine, D J

    2004-01-04

    This is a compilation of my patents issued from 1997 to 2002, generally describing interferometer techniques that modify the coherence properties of broad-bandwidth light and other waves, with applications to Doppler velocimetry, range finding, imaging and spectroscopy. Patents are tedious to read in their original form. In an effort to improve their readability I have embedded the Figures throughout the manuscript, put the Figure captions underneath the Figures, and added section headings. Otherwise I have resisted the temptation to modify the words, though I found many places which could use healthy editing. There may be minor differences with the official versions issued by the US Patent and Trademark Office, particularly in the claims sections. In my shock physics work I measured the velocities of targets impacted by flyer plates by illuminating them with laser light and analyzing the reflected light with an interferometer. Small wavelength changes caused by the target motion (Doppler effect) were converted into fringe shifts by the interferometer. Lasers having long coherence lengths were required for the illumination. While lasers are certainly bright sources, and their collimated beams are convenient to work with, they are expensive. Particularly if one needs to illuminate a wide surface area, then large amounts of power are needed. Orders of magnitude more power per dollar can be obtained from a simple flashlamp, or for that matter, a 50 cent light bulb. Yet these inexpensive sources cannot practically be used for Doppler velocimetry because their coherence length is extremely short, i.e. their bandwidth is much too wide. Hence the motivation for patents 1 & 2 is a method (White Light Velocimetry) for allowing use of these powerful but incoherent lamps for interferometry. The coherence of the illumination is modified by passing it through a preparatory interferometer.

  16. The Effects of Active Videogame Feedback and Practicing Experience on Children's Physical Activity Intensity and Enjoyment.

    PubMed

    Chen, Han; Sun, Haichun

    2017-08-01

    The study aims to explore the effects of receiving active videogame (AVG) feedback and playing experience on individuals' moderate-to-vigorous physical activity (MVPA) and perceived enjoyment. This was a within-subject design study. The participants included 36 (n = 15 and 21 for boys and girls, respectively) fourth graders enrolled in a rural elementary school in southern Georgia area. The experiment lasted for 6 weeks with each week including three sessions. The participants were assigned in either front row (sensor feedback) or back row (no sensor feedback) during practice, which was alternated in different sessions. Two different dance games were played during the study with each game implemented for 3 weeks. The MVPA was measured with GT3X+ accelerometers. Physical activity (PA) enjoyment was assessed after the completion of the first two and last two sessions of each game. A repeated one-way ANOVA (analysis of variance) was used to examine the effects of AVG feedback and game on MVPA. A repeated one-way MANOVA (multivariate analysis of variance) was conducted for each game to examine the effects of experience and AVG feedback on enjoyment and MVPA. No effects of AVG feedback were found for MVPA or enjoyment (P > 0.05). The effects of experience on MVPA were found for Just Dance Kids 2014 with experience decreased MVPA (P < 0.05). Students who practiced dance AVG without receiving feedback still demonstrated positive affection and accumulated similar MVPA than when practicing while receiving feedback. Experience for certain dance games tends to decrease PA intensity.

  17. meeting summary: Third COMPARE Workshop: A Model Intercomparison Experiment of Tropical Cyclone Intensity and Track Prediction.

    NASA Astrophysics Data System (ADS)

    Nagata, Masashi; Leslie, Lance; Kurihara, Yoshio; Elsberry, Russell L.; Yamasaki, Masanori; Kamahori, Hirotaka; Abbey, Robert, Jr.; Bessho, Kotaro; Calvo, Javier; Chan, Johnny C. L.; Clark, Peter; Desgagne, Michel; Hong, Song-You; Majewski, Detlev; Malguzzi, Piero; McGregor, John; Mino, Hiroshi; Murata, Akihiko; Nachamkin, Jason; Roch, Michel; Wilson, Clive

    2001-09-01

    The Third Comparison of Mesoscale Prediction and Research Experiment (COMPARE) workshop was held in Tokyo, Japan, on 13-15 December 1999, cosponsored by the Japan Meteorological Agency (JMA), Japan Science and Technology Agency, and the World Meteorological Organization. The third case of COMPARE focuses on an event of explosive tropical cyclone [Typhoon Flo (9019)] development that occurred during the cooperative three field experiments, the Tropical Cyclone Motion experiment 1990, Special Experiment Concerning Recurvature and Unusual Motion, and TYPHOON-90, conducted in the western North Pacific in August and September 1990. Fourteen models from nine countries have participated in at least a part of a set of experiments using a combination of four initial conditions provided and three horizontal resolutions. The resultant forecasts were collected, processed, and verified with analyses and observational data at JMA. Archived datasets have been prepared to be distributed to participating members for use in further evaluation studies. In the workshop, preliminary conclusions from the evaluation study were presented and discussed in the light of initiatives of the experiment and from the viewpoints of tropical cyclone experts. Initial conditions, depending on both large-scale analyses and vortex bogusing, have a large impact on tropical cyclone intensity predictions. Some models succeeded in predicting the explosive deepening of the target typhoon at least qualitatively in terms of the time evolution of central pressure. Horizontal grid spacing has a very large impact on tropical cyclone intensity prediction, while the impact of vertical resolution is less clear, with some models being very sensitive and others less so. The structure of and processes in the eyewall clouds with subsidence inside as well as boundary layer and moist physical processes are considered important in the explosive development of tropical cyclones. Follow-up research activities in this case

  18. The development of astronomical interferometry

    NASA Astrophysics Data System (ADS)

    Quirrenbach, Andreas

    2009-08-01

    Astronomical interferometry was pioneered by Fizeau and Michelson in the 19th century. In the 1920s, the first stellar diameters were measured. The development of radio interferometry began in the 1950s, and led to the construction of powerful synthesis arrays operating at cm, mm, and sub-mm wavelengths. Modern computer and control technology has enabled the interferometric combination of light from separate telescopes also in the visible and infrared regimes. Imaging with milliarcsecond resolution and astrometry with microarcsecond precision have thus become reality.

  19. High-Speed Digital Interferometry

    NASA Technical Reports Server (NTRS)

    De Vine, Glenn; Shaddock, Daniel A.; Ware, Brent; Spero, Robert E.; Wuchenich, Danielle M.; Klipstein, William M.; McKenzie, Kirk

    2012-01-01

    Digitally enhanced heterodyne interferometry (DI) is a laser metrology technique employing pseudo-random noise (PRN) codes phase-modulated onto an optical carrier. Combined with heterodyne interferometry, the PRN code is used to select individual signals, returning the inherent interferometric sensitivity determined by the optical wavelength. The signal isolation arises from the autocorrelation properties of the PRN code, enabling both rejection of spurious signals (e.g., from scattered light) and multiplexing capability using a single metrology system. The minimum separation of optical components is determined by the wavelength of the PRN code.

  20. Silvicultural options for early-successional stands in Maine: 6-year results of the Silvicultural Intensity and Species Composition Experiment

    Treesearch

    Andrew S. Nelson; Robert G. Wagner; Mike R. Saunders

    2014-01-01

    The Silvicultural Intensity and Species Composition (SIComp) experiment was installed in 2003 on a recently clearcut mixedwood site within the Penobscot Experimental Forest in east-central Maine. This study was initiated because the response of early-successional stands to various intensities of silviculture was poorly understood in the region. The goal of SIComp is to...

  1. Haze in the Grand Canyon: An evaluation of the Winter Haze Intensive Tracer Experiment

    SciTech Connect

    Not Available

    1990-10-01

    The Grand Canyon is one of the most spectacular natural sights on earth. Approximately 4 million visitors travel to Grand Canyon National Park (GCNP) each year to enjoy its majestic geological formations and intensely colored views. However, visibility in GCNP can be impaired by small increases in concentrations of fine suspended particles that scatter and absorb light; the resulting visibility degradation is perceived as haze. Sulfate particles are a major factor in visibility impairment at Grand Canyon in summer and winter. Many wintertime hazes at GCNP are believed to result from the accumulation of emissions from local sources during conditions of air stagnation, which occur more frequently in winter than in summer. In January and February 1987, the National Park Service (NPS) carried out a large-scale experiment known as the Winter Haze Intensive Tracer Experiment (WHITEX) to investigate the causes of wintertime haze in the region of GCNP and Canyonlands National Park. The overall objective of WHITEX was to assess the feasibility of attributing visibility impairment in specific geographic regions to emissions from a single point source. The experiment called for the injection of a tracer, deuterated methane (CD{sub 4}), into one of the stacks of the Navajo Generating Station (NGS), a major coal-fired power plant located 25 km from the GCNP boundary and 110 km northeast of Grand Canyon Village. A network of field stations was established in the vicinity -- mostly to the northeast of GCNP and NGS -- to measure CD{sub 4} concentrations, atmospheric aerosol and optical properties, and other chemical and physical attributes. 19 refs., 3 figs.

  2. Using atom interferometry to detect dark energy

    NASA Astrophysics Data System (ADS)

    Burrage, Clare; Copeland, Edmund J.

    2016-04-01

    We review the tantalising prospect that the first evidence for the dark energy driving the observed acceleration of the universe on giga-parsec scales may be found through metre scale laboratory-based atom interferometry experiments. To do that, we first introduce the idea that scalar fields could be responsible for dark energy and show that in order to be compatible with fifth force constraints, these fields must have a screening mechanism which hides their effects from us within the solar system. Particular emphasis is placed on one such screening mechanism known as the chameleon effect where the field's mass becomes dependent on the environment. The way the field behaves in the presence of a spherical source is determined and we then go on to show how in the presence of the kind of high vacuum associated with atom interferometry experiments, and when the test particle is an atom, it is possible to use the associated interference pattern to place constraints on the acceleration due to the fifth force of the chameleon field - this has already been used to rule out large regions of the chameleon parameter space and maybe one day will be able to detect the force due to the dark energy field in the laboratory.

  3. Parent experiences of communication with healthcare professionals in neonatal intensive care units: a qualitative systematic review protocol.

    PubMed

    Weis, Janne; Lundqvist, Pia

    2016-08-01

    The objectives of this review are to explore parents' experiences of communication with healthcare professionals and to identify the meaningfulness of communication to parents in the neonatal intensive care unit (NICU).More specifically, the objectives are to identify.

  4. Synchronous two-wavelength temporal interferometry

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqiong; Gao, Zhan; Qin, Jie; Li, Guangyu; Feng, Ziang; Wang, Shengjia

    2016-09-01

    Interferometry is an optical measuring method with the character of non-destructive, high sensitivity and high accuracy. However, its measurement range is limited by the phase ambiguity. Hence the method with two separate different wavelengths light source is introduced to enlarge the measurement range. As for the two-wavelength interferometry case, phase shifting is the traditional way to acquire the phase map, it needs to repeat the measurement twice, which means the measurement cannot be accomplished in real time. Hence to solve the problem, a temporal sequence interferometry has been used. This method can obtain the desired phase information in real time by using the Fourier transform methods of the interferogram recorded in a sequence while the object is being deformed. But, it is difficult to retrieve the phase information directly due to the multi extreme points in one period of the cosine function. In this paper, an algorithm based on the wavelet ridge analysis is adopted to retrieve the two wavelength phase fluctuation caused by the displacement simultaneously. The preliminary experiment is conducted and the results are compared with theoretical simulations to validate the proposed approach. The laser emits light with two wavelengths 532 nm and 473 nm, two separated interference patterns in time sequence are detected by the CCD camera in the same time. The overlapped interferograms of two colors are analyzed by this algorithm and the corresponding phase information are obtained. The maximum error value between the simulation and theory is 0.03 um and the relative error is 0.33%.

  5. GPU-accelerated image reconstruction for optical and infrared interferometry

    NASA Astrophysics Data System (ADS)

    Baron, Fabien; Kloppenborg, Brian

    2010-07-01

    The advent of GPU hardware and associated software libraries for scientific computing renders possible acceleration of parallelisable problems by a typical factor of 10-100. We present the first GPU-accelerated and open source image reconstruction software for optical/infrared interferometry, making use of the OpenCL library. Finally we evaluate how this improvement in speed may translate in terms of improvement in image reconstruction quality for currently computationnally intensive algorithms.

  6. Bain linguistique contre douche ecossaise: une experience de sejour intensif a l'etranger (Linguistic Immersion versus Hot-and-Cold Shower: An Experience of Intensive Overseas Stay).

    ERIC Educational Resources Information Center

    Smith, Sheila; Verguet, Patrick

    1979-01-01

    Describes the elaboration, over a period of three years, of a French language and civilization program consisting of linguistic and cultural preparation in England, followed by a one-week intensive linguistic and cultural experience in France. (AM)

  7. Evacuation of Intensive Care Units During Disaster: Learning From the Hurricane Sandy Experience.

    PubMed

    King, Mary A; Dorfman, Molly V; Einav, Sharon; Niven, Alex S; Kissoon, Niranjan; Grissom, Colin K

    2016-02-01

    Data on best practices for evacuating an intensive care unit (ICU) during a disaster are limited. The impact of Hurricane Sandy on New York City area hospitals provided a unique opportunity to learn from the experience of ICU providers about their preparedness, perspective, roles, and activities. We conducted a cross-sectional survey of nurses, respiratory therapists, and physicians who played direct roles during the Hurricane Sandy ICU evacuations. Sixty-eight health care professionals from 4 evacuating hospitals completed surveys (35% ICU nurses, 21% respiratory therapists, 25% physicians-in-training, and 13% attending physicians). Only 21% had participated in an ICU evacuation drill in the past 2 years and 28% had prior training or real-life experience. Processes were inconsistent for patient prioritization, tracking, transport medications, and transport care. Respondents identified communication (43%) as the key barrier to effective evacuation. The equipment considered most helpful included flashlights (24%), transport sleds (21%), and oxygen tanks and respiratory therapy supplies (19%). An evacuation wish list included walkie-talkies/phones (26%), lighting/electricity (18%), flashlights (10%), and portable ventilators and suction (16%). ICU providers who evacuated critically ill patients during Hurricane Sandy had little prior knowledge of evacuation processes or vertical evacuation experience. The weakest links in the patient evacuation process were communication and the availability of practical tools. Incorporating ICU providers into hospital evacuation planning and training, developing standard evacuation communication processes and tools, and collecting a uniform dataset among all evacuating hospitals could better inform critical care evacuation in the future.

  8. Measurement of neutron scattering lengths using neutron interferometry

    NASA Astrophysics Data System (ADS)

    Shahi, Chandra B.

    This thesis describes the details on building a new Neutron Interferometry and Optics Facility (NIOFa), the measurement of the incoherent neutron scattering length bi of 3He, and the measurement of the coherent neutron scattering length bc of 4He at National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). A new monochromatic beamline and facility has been installed at the NCNR devoted to neutron interferometry in the research areas of spin control, spin manipulation, quantum mechanics, quantum information science, spintronics, and material science. This facility is possible in part because of advances in decoherence free subspace interferometer designs that have demonstrated consistent contrast in the presence of vibrational noise; a major environmental constraint that has prevented neutron interferometry from being applied at other neutron facilities. This new facility, NIOFa, is located in the guide hall of the NCNR upstream of the existing Neutron Interferometry and Optics Facility (NIOF) and has several advantages over the NIOF including higher incident flux, better neutron polarization, and increased accessibility. The measurement of the incoherent neutron scattering length bi of 3He was done using a (220) single silicon crystal skew symmetric interferometer. This experiment requires both a polarized beam and a polarized target. We report bi = -2.35 +/- 0.014 (stat.) +/- 0.014 (syst.). This experiment is a revision of the previous experiment which was done in 2008, and partially explains the non-zero phase shift seen in 2008 experiment even if target cell was completely unpolarized. The measurement of the coherent neutron scattering length b c of the 4He was done using a (111) single silicon crystal interferometer. The neutron interferometry and optics facility at NIST had been used previously to determine the coherent scattering lengths for n- 1H, n-2H, and n-3He to less than 1% relative uncertainty. We report bc of the 4He

  9. Experience Corps Baltimore: Exploring the Stressors and Rewards of High-intensity Civic Engagement

    PubMed Central

    Varma, Vijay R.; Carlson, Michelle C.; Parisi, Jeanine M.; Tanner, Elizabeth K.; McGill, Sylvia; Fried, Linda P.; Song, Linda H.; Gruenewald, Tara L.

    2015-01-01

    Purpose: Experience Corps (EC) represents a high-intensity, intergenerational civic engagement activity where older adults serve as mentors and tutors in elementary schools. Although high-intensity volunteer opportunities are designed to enhance the health and well being of older adult volunteers, little is known about the negative and positive aspects of volunteering unique to intergenerational programs from the volunteer’s perspective. Design and Methods: Stressors and rewards associated with volunteering in EC were explored in 8 focus group discussions with 46 volunteers from EC Baltimore. Transcripts were coded for frequently expressed themes. Results: Participants reported stressors and rewards within 5 key domains: intergenerational (children’s problem behavior, working with and helping children, observing/facilitating improvement or transformation in a child, and developing a special connection with a child); external to EC (poor parenting and children’s social stressors); interpersonal (challenges in working with teachers and bonding/making social connections); personal (enjoyment, self-enhancement/achievement, and being/feeling more active); and structural (satisfaction with the structural elements of the EC program). Implications: Volunteers experienced unique intergenerational stressors related to children’s problem behavior and societal factors external to the EC program. Overall, intergenerational, interpersonal, and personal rewards from volunteering, as well as program structure may have balanced the stress associated with volunteering. A better understanding of stressors and rewards from high-intensity volunteer programs may enhance our understanding of how intergenerational civic engagement volunteering affects well being in later life and may inform project modifications to maximize such benefits for future volunteers and those they serve. PMID:24589989

  10. Experience Corps Baltimore: Exploring the Stressors and Rewards of High-intensity Civic Engagement.

    PubMed

    Varma, Vijay R; Carlson, Michelle C; Parisi, Jeanine M; Tanner, Elizabeth K; McGill, Sylvia; Fried, Linda P; Song, Linda H; Gruenewald, Tara L

    2015-12-01

    Experience Corps (EC) represents a high-intensity, intergenerational civic engagement activity where older adults serve as mentors and tutors in elementary schools. Although high-intensity volunteer opportunities are designed to enhance the health and well being of older adult volunteers, little is known about the negative and positive aspects of volunteering unique to intergenerational programs from the volunteer's perspective. Stressors and rewards associated with volunteering in EC were explored in 8 focus group discussions with 46 volunteers from EC Baltimore. Transcripts were coded for frequently expressed themes. Participants reported stressors and rewards within 5 key domains: intergenerational (children's problem behavior, working with and helping children, observing/facilitating improvement or transformation in a child, and developing a special connection with a child); external to EC (poor parenting and children's social stressors); interpersonal (challenges in working with teachers and bonding/making social connections); personal (enjoyment, self-enhancement/achievement, and being/feeling more active); and structural (satisfaction with the structural elements of the EC program). Volunteers experienced unique intergenerational stressors related to children's problem behavior and societal factors external to the EC program. Overall, intergenerational, interpersonal, and personal rewards from volunteering, as well as program structure may have balanced the stress associated with volunteering. A better understanding of stressors and rewards from high-intensity volunteer programs may enhance our understanding of how intergenerational civic engagement volunteering affects well being in later life and may inform project modifications to maximize such benefits for future volunteers and those they serve. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e

  11. Study Of Ho Lo-Speckle Interferometry

    NASA Astrophysics Data System (ADS)

    Chen, Jiabi

    1987-10-01

    Holo-speckle interferometry (HSI), as a 3-D displacement measuring method is studied in this paper. Three types of HSI are given. The average intensity distributions of its holographic and speckle interference fringes on the output planes are derived. The range of mea-surement and the problem of repositioning holograms for two-reference-beam HSI are disscussed. The results show that the upper limit of out-of-plane displacement is related to the parameters of the optical system and the in-plane displacement of specimen but the upper limit of in-plane displacement is determined by the paremeters only. The rigid body rotation of hologram in reconstruction process of two-reference-beam HSI influences the formation of interference fringes but the rigid body traslation does not have the influence.

  12. Influence of the excitation light intensity on the rate of fluorescence quenching reactions: pulsed experiments.

    PubMed

    Angulo, Gonzalo; Milkiewicz, Jadwiga; Kattnig, Daniel; Nejbauer, Michał; Stepanenko, Yuriy; Szczepanek, Jan; Radzewicz, Czesław; Wnuk, Paweł; Grampp, Günter

    2017-02-22

    The effect of multiple light excitation events on bimolecular photo-induced electron transfer reactions in liquid solution is studied experimentally. It is found that the decay of fluorescence can be up to 25% faster if a second photon is absorbed after a first cycle of quenching and recombination. A theoretical model is presented which ascribes this effect to the enrichment of the concentration of quenchers in the immediate vicinity of fluorophores that have been previously excited. Despite its simplicity, the model delivers a qualitative agreement with the observed experimental trends. The original theory by Burshtein and Igoshin (J. Chem. Phys., 2000, 112, 10930-10940) was created for continuous light excitation though. A qualitative extrapolation from the here presented pulse experiments to the continuous excitation conditions lead us to conclude that in the latter the order of magnitude of the increase of the quenching efficiency upon increasing the light intensity of excitation, must also be on the order of tens of percent. These results mean that the rate constant for photo-induced bimolecular reactions depends not only on the usual known factors, such as temperature, viscosity and other properties of the medium, but also on the intensity of the excitation light.

  13. Intensity-modulated radiotherapy for pituitary adenomas: The preliminary report of Cleveland Clinic experience

    SciTech Connect

    Mackley, Heath B. . E-mail: hmackley@alumni.upenn.edu; Reddy, Chandana A. M.S.; Lee, S.-Y.; Harnisch, Gayle A.; Mayberg, Marc R.; Hamrahian, Amir H.; Suh, John H.

    2007-01-01

    Purpose: Intensity-modulated radiotherapy (IMRT) is being increasingly used for the treatment of pituitary adenomas. However, there have been few published data on the short- and long-term outcomes of this treatment. This is the initial report of Cleveland Clinic's experience. Methods and Materials: Between February 1998 and December 2003, 34 patients with pituitary adenomas were treated with IMRT. A retrospective chart review was conducted for data analysis. Results: With a median follow-up of 42.5 months, the treatment has proven to be well tolerated, with performance status remaining stable in 90% of patients. Radiographic local control was 89%, and among patients with secretory tumors, 100% had a biochemical response. Only 1 patient required salvage surgery for progressive disease, giving a clinical progression free survival of 97%. The only patient who received more than 46 Gy experienced optic neuropathy 8 months after radiation. Smaller tumor volume significantly correlated with subjective improvements in nonvisual neurologic complaints (p = 0.03), and larger tumor volume significantly correlated with subjective worsening of visual symptoms (p = 0.05). New hormonal supplementation was required for 40% of patients. Younger patients were significantly more likely to require hormonal supplementation (p 0.03). Conclusions: Intensity-modulated radiation therapy is a safe and effective treatment for pituitary adenomas over the short term. Longer follow-up is necessary to determine if IMRT confers any advantage with respect to either tumor control or toxicity over conventional radiation modalities.

  14. Time Integrated Soft X-ray Imaging in High Intensity Laser Experiments (thesis)

    SciTech Connect

    Stafford, David

    2009-01-01

    2009 marks a significant achievement and the dawn of a new era in high intensity laser research with the final commissioning of all 192 beams at the National Ignition Facility (NIF). NIF is a department of energy (DOE) funded project more than 10 years in the making located at the Lawrence Livermore National Laboratory (LLNL). The following research was done as one of many preliminary experiments done to prepare for these historic events. The primary focus of the experimental campaign this paper addresses is to test and develop a thermal x-radiation source using a short pulse laser. This data is hoped to provide information about the thermal transport mechanisms important in the development of prediction models in High Energy Density (HED) science. One of several diagnostics fielded was a soft x-ray imager (SXRI) which is detailed in this paper. The SXRI will be used to measure the relative size of the heated region and also the relative level of specific x-ray emissions among several shot and target configurations. The laser system used was the Titan laser located in the Jupiter Laser Facility (JLF) at Lawrence Livermore National Laboratory (LLNL). Titan uses the JLF Janus Nd:glass laser west frontend system with a Optical Parametric Chirped Pulse Amplification (OPCPA) in place of the nanosecond oscillator. The system is capable of producing laser intensities of over a petawatt with several tens of joules delivered in the beam.

  15. A tunable, linac based, intense, broad-band THz source forpump-probe experiments

    SciTech Connect

    Schmerge, J.; Adolphsen, C.; Corbett, J.; Dolgashev, V.; Durr, H.; Fazio, M.; Fisher, A.; Frisch, J.; Gaffney, K.; Guehr, M.; Hastings, J.; Hettel, B.; Hoffmann, M.; Hogan, M.; Holtkamp, N.; Huang, X.; Huang, Z.; Kirchmann, P.; LaRue, J.; Limborg, C.; Lindenberg, A.; Loos, H.; Maxwell, T.; Nilsson, A.; Raubenheimer, T.; Reis, D.; Ross, M.; Shen, Z. -X.; Stupakov, G.; Tantawi, S.; Tian, K.; Wu, Z.; Xiang, D.; Yakimenko, V.

    2015-02-02

    We propose an intense THz source with tunable frequency and bandwidth that can directly interact with the degrees of freedom that determine the properties of materials and thus provides a new tool for controlling and directing these ultrafast processes as well as aiding synthesis of new materials with new functional properties. This THz source will broadly impact our understanding of dynamical processes in matter at the atomic-scale and in real time. Established optical pumping schemes using femtosecond visible frequency laser pulses for excitation are extended into the THz frequency regime thereby enabling resonant excitation of bonds in correlated solid state materials (phonon pumping), to drive low energy electronic excitations, to trigger surface chemistry reactions, and to all-optically bias a material with ultrashort electric fields or magnetic fields. A linac-based THz source can supply stand-alone experiments with peak intensities two orders of magnitude stronger than existing laser-based sources, but when coupled with atomic-scale sensitive femtosecond x-ray probes it opens a new frontier in ultrafast science with broad applications to correlated materials, interfacial and liquid phase chemistry, and materials in extreme conditions.

  16. Iranian nurses’ experiences of brain dead donors care in intensive care units: A phenomenological study

    PubMed Central

    Salehi, Shayesteh; Kanani, Tahereh; Abedi, Heidarali

    2013-01-01

    Background: Care of brain dead donors is complex, critical, and sensitive and has a direct and positive impact on the end result of organ and tissue transplantation process. This study describes the nurses’ experiences of care of brain dead donors in intensive care units (ICU). Materials and Methods: This research was performed by phenomenological method that is a qualitative approach. Purposive sampling was used to gather the data. The researcher reached to data saturation by deep interviews conducted with eight participants from ICU nurses in Isfahan hospitals who cooperated in care of brain dead donors. Data analysis was performed according to Colaizzi analysis method. Results: Interviews were analyzed and the results of analysis led to “Excruciating tasks” as the main theme formed by psychological effects of facing the situation, heavy and stressful care, defect of scientific knowledge, conflict between feeling and duty, outcome of attitude change in behavior, emotional responses to perceived psychological afflictions, doubt to medical diagnosis, spiritual perceptions, and biological responses when faced with the situation. Conclusion: Caring of brain dead organ donors is difficult and stressful for intensive care nurses and can be a threat for nurses’ health and quality of nursing care. So, providing suitable physical, mental, and working conditions is necessary to make suitable background to maintain and increase nurses’ health and quality of care and effective cooperation of this group of health professionals in organ procurement process. PMID:24554946

  17. The Space Interferometry Mission

    NASA Technical Reports Server (NTRS)

    Unwin, Stephen C.

    1998-01-01

    The Space Interferometry Mission (SIM) is the next major space mission in NASA's Origins program after SIRTF. The SIM architecture uses three Michelson interferometers in low-earth orbit to provide 4 microarcsecond precision absolute astrometric measurements on approx. 40,000 stars. SIM will also provide synthesis imaging in the visible waveband to a resolution of 10 milliarcsecond, and interferometric nulling to a depth of 10(exp -4). A near-IR (1-2 micron) capability is being considered. Many key technologies will be demonstrated by SIM that will be carried over directly or can be readily scaled to future Origins missions such as TPF. The SIM spacecraft will carry a triple Michelson interferometer with baselines in the 10 meter range. Two interferometers act as high precision trackers, providing attitude information at all time, while the third one conducts the science observations. Ultra-accurate laser metrology and active systems monitor the systematic errors and to control the instrument vibrations in order to reach the 4 microarcsecond level on wide-angle measurements. SIM will produce a wealth of new astronomical data. With an absolute positional precision of 4 microarcsecond, SIM will improve on the best currently available measures (the Hipparcos catalog) by 2 or 3 orders of magnitude, providing parallaxes accurate to 10% and transverse velocities to 0.2 km/s anywhere in the Galaxy, to stars as faint as 20th magnitude. With the addition of radial velocities, knowledge of the 6-dimension phase space for objects of interest will allow us to attack a wide array of previously inaccessible problems such as: search for planets down to few earth masses; calibration of stellar luminosities and by means of standard candles, calibration of the cosmic distance scale; detecting perturbations due to spiral arms, disk warps and central bar in our galaxy; probe of the gravitational potential of the Galaxy, several kiloparsecs out of the galactic plane; synthesis imaging

  18. The Space Interferometry Mission

    NASA Technical Reports Server (NTRS)

    Unwin, Stephen C.

    1998-01-01

    The Space Interferometry Mission (SIM) is the next major space mission in NASA's Origins program after SIRTF. The SIM architecture uses three Michelson interferometers in low-earth orbit to provide 4 microarcsecond precision absolute astrometric measurements on approx. 40,000 stars. SIM will also provide synthesis imaging in the visible waveband to a resolution of 10 milliarcsecond, and interferometric nulling to a depth of 10(exp -4). A near-IR (1-2 micron) capability is being considered. Many key technologies will be demonstrated by SIM that will be carried over directly or can be readily scaled to future Origins missions such as TPF. The SIM spacecraft will carry a triple Michelson interferometer with baselines in the 10 meter range. Two interferometers act as high precision trackers, providing attitude information at all time, while the third one conducts the science observations. Ultra-accurate laser metrology and active systems monitor the systematic errors and to control the instrument vibrations in order to reach the 4 microarcsecond level on wide-angle measurements. SIM will produce a wealth of new astronomical data. With an absolute positional precision of 4 microarcsecond, SIM will improve on the best currently available measures (the Hipparcos catalog) by 2 or 3 orders of magnitude, providing parallaxes accurate to 10% and transverse velocities to 0.2 km/s anywhere in the Galaxy, to stars as faint as 20th magnitude. With the addition of radial velocities, knowledge of the 6-dimension phase space for objects of interest will allow us to attack a wide array of previously inaccessible problems such as: search for planets down to few earth masses; calibration of stellar luminosities and by means of standard candles, calibration of the cosmic distance scale; detecting perturbations due to spiral arms, disk warps and central bar in our galaxy; probe of the gravitational potential of the Galaxy, several kiloparsecs out of the galactic plane; synthesis imaging

  19. Caring for dying infants: experiences of neonatal intensive care nurses in Hong Kong.

    PubMed

    Yam, B M; Rossiter, J C; Cheung, K Y

    2001-09-01

    Ten registered nurses working in a neonatal intensive care unit in Hong Kong were interviewed to explore their experiences of caring for infants whose disease is not responsive to curative treatment, their perceptions of palliative care, and factors influencing their care. Eight categories emerged from the content analysis of the interviews: disbelieving; feeling ambivalent and helpless; protecting emotional self; providing optimal physical care to the infant; providing emotional support to the family; expressing empathy; lack of knowledge and counselling skills; and conflicting values in care. The subtle cultural upbringing and socialization in nurse training and workplace environment also contributed to their moral distress. Hospital and nurse administrators should consider different ways of facilitating palliative care in their acute care settings. For example, by culture-specific death education, peer support groups, bereavement teams, modification of departmental policies, and a supportive work environment. Future research could include the identification of family needs and coping as well as ethical decision-making among nurses.

  20. Gas Filled RF Resonator Hadron Beam Monitor for Intense Neutrino Beam Experiments

    SciTech Connect

    Yonehara, Katsuya; Abrams, Robert; Dinkel, Holly; Freemire, Ben; Johnson, Rolland; Kazakevich, Grigory; Tollestrup, Alvin; Zwaska, Robert

    2016-06-01

    MW-class beam facilities are being considered all over the world to produce an intense neutrino beam for fundamental particle physics experiments. A radiation-robust beam monitor system is required to diagnose the primary and secondary beam qualities in high-radiation environments. We have proposed a novel gas-filled RF-resonator hadron beam monitor in which charged particles passing through the resonator produce ionized plasma that changes the permittivity of the gas. The sensitivity of the monitor has been evaluated in numerical simulation. A signal manipulation algorithm has been designed. A prototype system will be constructed and tested by using a proton beam at the MuCool Test Area at Fermilab.

  1. Validating under-resolved turbulence intensities for PIV experiments in canonical wall-bounded turbulence

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Kevin; Monty, J. P.; Hutchins, N.

    2016-08-01

    The discrepancy between measured turbulence intensity obtained from experiments in wall-bounded turbulence and the fully resolved reference results (usually from DNS datasets) are often attributed to spatial resolution issues, especially in PIV measurements due to the presence of spatial averaging within the interrogation region/volume. In many cases, in particular at high Reynolds numbers (where there is a lack of DNS data), there is no attempt to verify that this is the case. There is a risk that attributing unexpected PIV statistics to spatial resolution, without careful checks, could mask wider problems with the experimental setup or test facility. Here, we propose a robust technique to validate the under-resolved PIV obtained turbulence intensity profiles for canonical wall-bounded turbulence. This validation scheme is independent of Reynolds number and does not rely on empirical functions. It is based on arguments that (1) the viscous-scaled small-scale turbulence energy is invariant with Reynolds number and that (2) the spatially under-resolved measurement is sufficient to capture the large-scale energy. This then suggests that we can estimate the missing energy from volume-filtered DNS data at much lower Reynolds numbers. Good agreement is found between the experimental results and estimation profiles for all three velocity components, demonstrating that the estimation tool successfully computes the missing energy for given spatial resolutions over a wide range of Reynolds numbers. A database for a canonical turbulent boundary layer and associated MATLAB function are provided that enable this missing energy to be calculated across a range of interrogation volume sizes, so that users do not require access to raw DNS data. This methodology and tool will provide PIV practitioners, investigating canonical wall-bounded turbulent flow with a convenient check of the effects of spatial resolution on a given experiment.

  2. New Methods in Moire Interferometry

    NASA Astrophysics Data System (ADS)

    Czarnek, Robert

    Experimental observations and measurements are the essential source of information necessary for correct development of mathematical models of real materials. Moire interferometry offers high sensitivity in full-field measurements of the in-plane displacements on the surface of the specimen. The (+OR-)45(DEGREES) method of moire interferometry increases the efficiency of a three-beam interferometer making its use outside of an optical laboratory more practical. Analysis of the (+OR-)45(DEGREES) method is provided. A concept of the vector representation of the fringe gradient is introduced and used in the analysis. Although existing systems require coherent light, the proposed system can use a relatively broad spectral bandwidth. Features that are related to the vibration sensitivity of such an instrument are investigated analytically. The basic concepts of an achromatic moire interferometry system are developed. Attachment of the critical elements of the system to the specimen solves the problem of relative rigid body motions, including vibrations, between the specimen and the virtual reference grating. Application of a laser diode light source reduces size, weight and cost of the interferometer making moire interferometry more practical for most materials testing laboratories. Laboratory tests confirmed the developed methods. This work enhances the probability of successful construction of a portable moire interferometer for measurements outside of the optical laboratory, in a mechanical testing or field environment.

  3. Polarimetric Interferometry - Remote Sensing Applications

    DTIC Science & Technology

    2007-02-01

    This lecture is mainly based on the work of S.R. Cloude and presents examples for remote sensing applications Polarimetric SAR Interferometry...PolInSAR). PolInSAR has its origins in remote sensing and was first developed for applications in 1997 using SIRC L-Band data [1,2]. In its original form it

  4. Parents' experiences of communication with neonatal intensive-care unit staff: an interview study.

    PubMed

    Wigert, Helena; Dellenmark Blom, Michaela; Bry, Kristina

    2014-12-10

    An infant's admission to a neonatal intensive-care unit (NICU) inevitably causes the parents emotional stress. Communication between parents and NICU staff is an essential part of the support offered to the parents and can reduce their emotional stress. The aim of this study was to describe parents' experiences of communication with NICU staff. A hermeneutic lifeworld interview study was performed with 18 families whose children were treated in the level III NICU at a university hospital in Sweden. The interviews were analysed to gain an interpretation of the phenomenon of how parents in the NICU experienced their communication with the staff, in order to find new ways to understand their experience. Parents' experience of communication with the staff during their infant's stay at the NICU can be described by the main theme 'being given attention or ignored in their emotional situation'. The main theme derives from three themes; (1) meeting a fellow human being, (2) being included or excluded as a parent and (3) bearing unwanted responsibility. This study shows that parents experienced communication with the NICU staff as essential to their management of their situation. Attentive communication gives the parents relief in their trying circumstances. In contrast, lack of communication contributes to feelings of loneliness, abandonment and unwanted responsibility, which adds to the burden of an already difficult situation. The level of communication in meetings with staff can have a decisive influence on parents' experiences of the NICU. The staff should thus be reminded of their unique position to help parents handle their emotional difficulties. The organization should facilitate opportunities for good communication between parents and staff through training, staffing and the physical health care environment.

  5. Diffusion in solids with holographic interferometry

    NASA Astrophysics Data System (ADS)

    Liu, Dingyu

    1996-12-01

    It is of great importance for the formation of p-n junction in semiconductors by penetrating some impurities through the depth near the surface, so it has long been paid attention to control the concentration distribution of impurities during the diffusion process. In recent years, ionic carburizing, and ion bombardment penetration etc. for the treatment of metal surface have also attracted by material sciences. It requires that the diffusion depth and the diffusion time of the impurities should be under precise control. Different methods, such as the method of radioisotopic detection and the method of chemical analysis have been adopted, however, the reports of different workers are very different, especially in the real time measurement, so, finding new method is never ending. In 1984, H. Fenichel have performed experiments on the solutions of table salt and sugar with the method of holographic interferometry. As for metals which are opaque for the visible light, but they become transparent by making them into a very thin film so that, in principle, the diffusion of atoms within a film is capable of measure by holographic interferometry. Alternatively, the electromagnetic waves within 1 - 70 micrometers wavelengths may be utilized, some materials, such as high purified germanium and silicon are good materials for infrared transmission. Some fluorides of alkaline-earth metals have high transmittance in the range of 1 - 8 micrometers , the concentration of impurities in the semiconductor and metal surface treatment are of 1015 - 1020 atoms per cubic cm, which is capable of detection.

  6. Nurses’ Experiences of Futile Care at Intensive Care Units: A Phenomenological Study

    PubMed Central

    Yekefallah, Leili; Ashktorab, Tahereh; Manoochehri, Houman; Hamid, Alavi Majd

    2015-01-01

    The concept and meaning of futile care depends on the existing culture, values, religion, beliefs, medical achievements and emotional status of a country. We aimed to define the concept of futile care in the viewpoints of nurses working in intensive care units (ICUs). In this phenomenological study, the experiences of 25 nurses were explored in 11 teaching hospitals affiliated to Social Security Organization in Ghazvin province in the northwest of Iran. Personal interviews and observations were used for data collection. All interviews were recorded as well as transcribed and codes, subthemes and themes were extracted using Van Manen’s analysis method. Initially, 191 codes were extracted. During data analysis and comparison, the codes were reduced to 178. Ultimately, 9 sub-themes and four themes emerged: uselessness, waste of resources, torment, and aspects of futility. Nurses defined futile care as “useless, ineffective care giving with wastage of resources and torment of both patients and nurses having nursing and medical aspects” As nurses play a key role in managing futile care, being aware of their experiences in this regard could be the initial operational step for providing useful care as well as educational programs in ICUs. Moreover, the results of this study could help nursing managers adopt supportive approaches to reduce the amount of futile care which could in turn resolve some of the complications nurses face at these wards such as burnout, ethical conflicts, and leave. PMID:25946928

  7. Spectroscopic Analysis of High Intensity Laser Beam Jets Interaction Experiments on the Leopard Laser at UNR

    NASA Astrophysics Data System (ADS)

    Petkov, E. E.; Weller, M. E.; Kantsyrev, V. L.; Safronova, A. S.; Moschella, J. J.; Shrestha, I.; Shlyapsteva, V. V.; Stafford, A.; Keim, S. F.; University of Nevada Reno Team

    2013-10-01

    Results of Ar gas-puff experiments performed on the high power Leopard laser at UNR are presented. Flux density of laser radiation in focal spot was up to 2 × 1016 W/cm2 (pulse duration was 0.8 ns and laser wavelength was 1.057 μm). Specifically, spectroscopic analysis of K-shell Ar spectra are investigated and compared as functions of the orientation of the laser beam to linear gas jet. The laser beam axis was positioned either along the jet plane or orthogonal to it at a distance of 1 mm from the nozzle output. The diagnostics used included a time-integrated x-ray spectrometer along with a set of filtered Si diodes with various cutoff energies. In order to identify lines, a non-local thermodynamic equilibrium (non-LTE) kinetic model was utilized and was also used to determine plasma parameters such as electron temperature and density. The importance of the spectroscopic study of high intensity laser beam-jets interaction experiments is discussed. This work was supported by the Defense Threat Reduction Agency, Basic Research Award # HDTRA1-13-1-0033, to University of Nevada, Reno, and in part by the DOE/NNSA Cooperative agreements DE-NA0001984 and DE-FC52-06NA27616.

  8. Correlated-intensity velocimeter for arbitrary reflector for laser-produced plasma experiments

    SciTech Connect

    Wang Zhehui; Luo Shengnian; Barnes, Cris W.; Briggs, Matthew E.; Paisley, Dennis L.; Paul, Stephen F.

    2006-10-15

    A laser-based technique, called correlated-intensity velocimeter for arbitrary reflector (CIVAR), is described for velocity measurement of reflecting surfaces in real time. Velocity versus time is an important measurement in laser-produced high-energy density plasma experiments because the motion of the surface depends on both the equation of the state of the surface material and laser-produced plasma. The physics and working principle of CIVAR are the same as those of a previous concept that resolves Doppler shift of plasma light emission using a pair of narrow passband interference filters. One unique feature of CIVAR is that a reflected laser beam is used instead of plasma emission. Therefore, CIVAR is applicable to both emitting and nonemitting reflecting surfaces. Other advantages of CIVAR include its simplicity, lower cost, and unambiguous data analysis that can be fully automated. The design of a single-point CIVAR is described in detail with emphasis on laser wavelength selection and signal-to-noise ratio. The single-point CIVAR system can be expanded into a multiple-point system straightforwardly. It is possible to use CIVAR concept to construct a two-dimensional imaging system for a nonuniform velocity field of a large reflecting surface; such a velocity imaging system may have applications beyond laser-produced plasma experiments, for example, in shock compression of condensed matter.

  9. Experiences of mothers of infants with neonatal abstinence syndrome in the neonatal intensive care unit.

    PubMed

    Cleveland, Lisa M; Bonugli, Rebecca

    2014-01-01

    To describe the experiences of mothers of infants with neonatal abstinence syndrome (NAS) in the neonatal intensive care unit (NICU). Qualitative description. We recruited participants from community-based, out-patient, addiction treatment facilities in a large urban city in the southwestern region of the United States. A convenience sample of 15 Hispanic, substance addicted mothers of infants with NAS participated. We conducted semistructured, individual, interviews and analyzed the data using qualitative content analysis. First, we analyzed the data independently and then discussed the themes until a consensus was reached. We identified four themes: (a) understanding addiction, (b) watching the infant withdraw, (c) judging, and (d) trusting the nurses. The participants felt there was a lack of understanding concerning addiction that was particularly noted when interacting with the nurses. They shared their feelings of guilt and shame when observing their infants withdrawing. The participants felt judged by the nurses for having used illicit drugs during pregnancy. Feeling judged interfered with the participants' ability to trust the nurses. These findings provide nurses with a better understanding of the experiences of mothers who have addiction problems and may lead to more customized nursing care for this high-risk population of mothers and their infants. © 2014 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  10. Patient experiences with intensive combination-treatment strategies with glucocorticoids for early rheumatoid arthritis.

    PubMed

    Meyfroidt, Sabrina; Van der Elst, Kristien; De Cock, Diederik; Joly, Johan; Westhovens, René; Hulscher, Marlies; Verschueren, Patrick

    2015-03-01

    To investigate patients' experiences with intensive combination-treatment strategies with glucocorticoids (ICTS-GCs) in the early phase of early rheumatoid arthritis (ERA) treatment. We interviewed 26 participants individually, 4-6 months after initiation of ICTS-GCs (t1). Fourteen participants from the same sample took part in one of three focus groups at least 1 year after treatment initiation (t2). Each interview was audio-recorded, literally transcribed and thematically coded. The participants described concerns and feelings about ICTS-GCs that changed over time; for example, a fear of side effects diminished when the treatment effects were beneficial or expected side effects did not materialize. Moreover, participants indicated additional information needs at t1 and t2. The most used sources of information were healthcare professionals, relatives, and the Internet. Furthermore, participants reported on their relationship with healthcare professionals and the need for trust and reassurance, especially at t1. Lastly, participants described their personal self-management strategies. Despite their concerns at treatment initiation, most participants had positive experiences with ICTS-GCs. Healthcare professionals should be aware that, in the early phase of treatment, they can address patients' concerns, they are the most important information source, they need to create a relationship of trust, and guide patients in self-management strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Radiation-Hydrodynamic Simulation of Experiments With Intense Lasers Generating Collisionless Interpenetrating Plasmas

    NASA Astrophysics Data System (ADS)

    Grosskopf, Michael; Drake, R.; Kuranz, C.; Park, H.; Kugland, N.; Pollaine, S.; Ross, J.; Remington, B.; Spitkovsky, A.; Gargate, L.; Gregori, G.; Bell, A.; Murphy, C.; Meinecke, J.; Reville, B.; Sakawa, Y.; Kuramitsu, Y.; Takabe, H.; Froula, D.; Fiksel, G.; Miniati, F.; Koenig, M.; Ravasio, A.; Liang, E.; Woolsey, N.

    2012-05-01

    Collisionless shocks, shocks generated by plasma wave interactions in regions where the collisional mean-free-path for ions is long compared to the length scale for instabilities that generate magnetic fields, are found in many astrophysical systems such as supernova remnants and planetary bow shocks. Generating conditions to investigate collisionless shock physics is difficult to achieve in a laboratory setting; however, high-energy-density physics facilities have made this a possibility. Experiments whose goal is to investigate the production and growth of magnetic fields in collisionless shocks in laboratory-scale systems are being carried out on intense lasers, several of which are measuring the plasma properties and magnetic field strength in counter-streaming, collisionless flows generated by laser ablation. This poster reports radiation-hydrodynamic simulations using the CRASH code to model the ablative flow of plasma generated in order to assess potential designs, as well as infer properties of collected data from previous experiments. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-NA0000850.

  12. "It's intense, you know." Nurses' experiences in caring for patients requesting euthanasia.

    PubMed

    Denier, Yvonne; Dierckx de Casterlé, Bernadette; De Bal, Nele; Gastmans, Chris

    2010-02-01

    The Belgian Act on Euthanasia came into force on 23 September 2002, making Belgium the second country--after the Netherlands--to decriminalize euthanasia under certain due-care conditions. Since then, Belgian nurses have been increasingly involved in euthanasia care. In this paper, we report a qualitative study based on in-depth interviews with 18 nurses from Flanders (the Dutch-speaking part of Belgium) who have had experience in caring for patients requesting euthanasia since May 2002 (the approval of the Act). We found that the care process for patients requesting euthanasia is a complex and dynamic process, consisting of several stages, starting from the period preceding the euthanasia request and ending with the aftercare stage. When asked after the way in which they experience their involvement in the euthanasia care process, all nurses described it as a grave and difficult process, not only on an organizational and practical level, but also on an emotional level. "Intense" is the dominant feeling experienced by nurses. This is compounded by the presence of other feelings such as great concern and responsibility on the one hand, being content in truly helping the patient to die serenely, and doing everything in one's power to contribute to this; but also feeling unreal and ambivalent on the other hand, because death is arranged. Nurses feel a discrepancy, because although it is a nice death, which happens in dignity and with respect, it is also an unnatural death. The clinical ethical implications of these findings are discussed.

  13. Autonomy gone awry: a cross-cultural study of parents' experiences in neonatal intensive care units.

    PubMed

    Orfali, Kristina; Gordon, Elisa J

    2004-01-01

    This paper examines parents' experiences of medical decision-making and coping with having a critically ill baby in the Neonatal Intensive Care Unit (NICU) from a cross-cultural perspective (France vs. U.S.A.). Though parents' experiences in the NICU were very similar despite cultural and institutional differences, each system addresses their needs in a different way. Interviews with parents show that French parents expressed overall higher satisfaction with the care of their babies and were better able to cope with the loss of their child than American parents. Central to the French parents' perception of autonomy and their sense of satisfaction were the strong doctor-patient relationship, the emphasis on medical certainty in prognosis versus uncertainty in the American context, and the "sentimental work" provided by the team. The American setting, characterized by respect for parental autonomy, did not necessarily translate into full parental involvement in decision-making, and it limited the rapport between doctors and parents to the extent of parental isolation. This empirical comparative approach fosters a much-needed critique of philosophical principles by underscoring, from the parents' perspective, the lack of "emotional work" involved in the practice of autonomy in the American unit compared to the paternalistic European context. Beyond theoretical and ethical arguments, we must reconsider the practice of autonomy in particularly stressful situations by providing more specific means to cope, translating the impersonal language of "rights" and decision-making into trusting, caring relationships, and sharing the responsibility for making tragic choices.

  14. Coping with the neonatal intensive care unit experience: parents' strategies and views of staff support.

    PubMed

    Smith, Vincent C; Steelfisher, Gillian K; Salhi, Carmel; Shen, Lisa Y

    2012-01-01

    It is stressful for parents to have an infant in the neonatal intensive care unit (NICU). To better understand the parents' experience and the role of staff, we examined parental reports of their NICU experiences, coping strategies, and views of the ways NICU staff supported them. Between June and July 2007, we interviewed 29 current and graduate parents from the study institution's NICU. A trained researcher conducted all interviews, which were recorded and transcribed. This was a qualitative analysis of prospectively collected interview data. Parents used the following coping strategies: (1) participating in care of the child; (2) getting away from the NICU; (3) gathering information; (4) involvement of friends and family; and (5) engagement with other NICU parents. Staff can support the parents' coping strategies in the following ways: (1) facilitating participation of the parents with the infant's care; (2) emphasizing documentation of the infant's progress; (3) demonstrating affection for the infant; (4) addressing concerns that make parents hesitant to leave the NICU; (5) providing accurate, consistent clinical information; (6) limiting unscheduled nonemergency phone calls; and (7) arranging voluntarily activities or programs in which parents whose infants have similar medical conditions may interact.

  15. Precision measurements with atom interferometry

    NASA Astrophysics Data System (ADS)

    Schubert, Christian; Abend, Sven; Schlippert, Dennis; Ertmer, Wolfgang; Rasel, Ernst M.

    2017-04-01

    Interferometry with matter waves enables precise measurements of rotations, accelerations, and differential accelerations [1-5]. This is exploited for determining fundamental constants [2], in fundamental science as e.g. testing the universality of free fall [3], and is applied for gravimetry [4], and gravity gradiometry [2,5]. At the Institut für Quantenoptik in Hannover, different approaches are pursued. A large scale device is designed and currently being set up to investigate the gain in precision for gravimetry, gradiometry, and fundamental tests on large baselines [6]. For field applications, a compact and transportable device is being developed. Its key feature is an atom chip source providing a collimated high flux of atoms which is expected to mitigate systematic uncertainties [7,8]. The atom chip technology and miniaturization benefits from microgravity experiments in the drop tower in Bremen and sounding rocket experiments [8,9] which act as pathfinders for space borne operation [10]. This contribution will report about our recent results. The presented work is supported by the CRC 1227 DQ-mat, the CRC 1128 geo-Q, the RTG 1729, the QUEST-LFS, and by the German Space Agency (DLR) with funds provided by the Federal Ministry of Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under Grant No. DLR 50WM1552-1557. [1] P. Berg et al., Phys. Rev. Lett., 114, 063002, 2015; I. Dutta et al., Phys. Rev. Lett., 116, 183003, 2016. [2] J. B. Fixler et al., Science 315, 74 (2007); G. Rosi et al., Nature 510, 518, 2014. [3] D. Schlippert et al., Phys. Rev. Lett., 112, 203002, 2014. [4] A. Peters et al., Nature 400, 849, 1999; A. Louchet-Chauvet et al., New J. Phys. 13, 065026, 2011; C. Freier et al., J. of Phys.: Conf. Series 723, 012050, 2016. [5] J. M. McGuirk et al., Phys. Rev. A 65, 033608, 2002; P. Asenbaum et al., arXiv:1610.03832. [6] J. Hartwig et al., New J. Phys. 17, 035011, 2015. [7] H. Ahlers et al., Phys. Rev. Lett. 116, 173601

  16. Acute confusion and unreal experiences in intensive care patients in relation to the ICU syndrome. Part II.

    PubMed

    Granberg, A; Engberg, I B; Lundberg, D

    1999-02-01

    The intensive care unit syndrome (ICU syndrome) is defined as an altered emotional state occurring in a highly stressful environment, which may manifest itself in various forms such as delirium, confusion, crazy dreams or unreal experiences. The purpose of this part of a study of patients' experiences is to describe and illuminate patients' experiences of acute confusion, disorientation, wakefulness, dreams and nightmares during and after their stay in the ICU. The data were obtained from 19 ventilated patients, who were interviewed twice and had stayed at least 36 hours in the ICU, the first interview being about one week after discharge from the ICU, and the second 4-8 weeks later. The hermeneutic approach used when interpreting and analysing the text from the interviews revealed that patients' experiences of unreal experiences were often associated with intense fear. Intense or continuous unbearable fear seems to result in frightening unreal experiences, which further increase the level of fear. Care actions or caring relationships with relatives or nurses can reduce this fear, which can help to prevent the occurrence and/or duration and intensity of the unreal experiences. Trust and confidence in nurses or significant others and feelings of self-control or trust in self-control seemed to reduce the risk of unreal experiences so that adverse stimuli might only trigger a mild confusion.

  17. The Narrabri Stellar Intensity Interferometer: a 50th birthday tribute

    NASA Astrophysics Data System (ADS)

    Tuthill, Peter G.

    2014-07-01

    This year marks the 50th anniversary since the first scientific measurements were produced with the Narrabri Stellar Intensity Interferometer, which was constructed in the early 1960's by Robert Hanbury Brown and Richard Twiss. A collaboration between the Universities of Sydney and Manchester, the interferometer was the culmination of a series of experiments which pioneered the technique of intensity interferometry. The immediate controversy surrounding the quantum implications of the technique enveloped some of the most eminent physicists of the day, sparking a debate about nonlocal effects and optical coherence. A full explanation of the workings of the intensity interferometer in a quantum context was finally put forward by Roy Glauber, ultimately earning him the 2005 Nobel Prize in Physics. The intensity interferometer rekindled the field of high resolution stellar imaging, which had been extinguished for a half century (following the failure of Pease's 50-foot beam on Mt Wilson), while delivering the first ever measurements of the sizes of normal stars - establishing an effective temperature scaling relationship which has underpinned stellar astronomy for 50 years. This directly paved the way for the next generation of Michelson Stellar Interferometers. Intensity interferometry itself has found application in several fields (notably particle physics), and plans are in active development for modern reprises within stellar interferometry. However undoubtedly the greatest legacy lies in the Hanbury Brown Twiss (HBT) effect being the foundational experiment for what is now known as Quantum Optics - a field which underpins a huge sector of the technology which enables our modern world. This invited review discuses the development of the interferometer, including the controversy that its underlying principles generated within the contemporary physics community. The core scientific output generated by the instrument is presented, together with the impact of the

  18. Moral distress in intensive care unit professionals is associated with profession, age, and years of experience.

    PubMed

    Dodek, Peter M; Wong, Hubert; Norena, Monica; Ayas, Najib; Reynolds, Steven C; Keenan, Sean P; Hamric, Ann; Rodney, Patricia; Stewart, Miriam; Alden, Lynn

    2016-02-01

    To determine which demographic characteristics are associated with moral distress in intensive care unit (ICU) professionals. We distributed a self-administered, validated survey to measure moral distress to all clinical personnel in 13 ICUs in British Columbia, Canada. Each respondent to the survey also reported their age, sex, and years of experience in the ICU where they were working. We used multivariate, hierarchical regression to analyze relationships between demographic characteristics and moral distress scores, and to analyze the relationship between moral distress and tendency to leave the workplace. Response rates to the surveys were the following: nurses--428/870 (49%); other health professionals (not nurses or physicians)--211/452 (47%); physicians--30/68 (44%). Nurses and other health professionals had higher moral distress scores than physicians. Highest ranked items associated with moral distress were related to cost constraints and end-of-life controversies. Multivariate analyses showed that age is inversely associated with moral distress, but only in other health professionals (rate ratio [95% confidence interval]: -7.3 [-13.4, -1.2]); years of experience is directly associated with moral distress, but only in nurses (rate ratio (95% confidence interval):10.8 [2.6, 18.9]). The moral distress score is directly related to the tendency to leave the ICU job, in both the past and present, but only for nurses and other non-physician health professionals. Moral distress is higher in ICU nurses and other non-physician professionals than in physicians, is lower with older age for other non-physician professionals but greater with more years of experience in nurses, and is associated with tendency to leave the job. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Ensemble experiments using a nested LETKF system to reproduce intense vortices associated with tornadoes of 6 May 2012 in Japan

    NASA Astrophysics Data System (ADS)

    Seko, Hiromu; Kunii, Masaru; Yokota, Sho; Tsuyuki, Tadashi; Miyoshi, Takemasa

    2015-12-01

    Experiments simulating intense vortices associated with tornadoes that occurred on 6 May 2012 on the Kanto Plain, Japan, were performed with a nested local ensemble transform Kalman filter (LETKF) system. Intense vortices were reproduced by downscale experiments with a 12-member ensemble in which the initial conditions were obtained from the nested LETKF system analyses. The downscale experiments successfully generated intense vortices in three regions similar to the observed vortices, whereas only one tornado was reproduced by a deterministic forecast. The intense vorticity of the strongest tornado, which was observed in the southernmost region, was successfully reproduced by 10 of the 12 ensemble members. An examination of the results of the ensemble downscale experiments showed that the duration of intense vorticities tended to be longer when the vertical shear of the horizontal wind was larger and the lower airflow was more humid. Overall, the study results show that ensemble forecasts have the following merits: (1) probabilistic forecasts of the outbreak of intense vortices associated with tornadoes are possible; (2) the miss rate of outbreaks should decrease; and (3) environmental factors favoring outbreaks can be obtained by comparing the multiple possible scenarios of the ensemble forecasts.

  20. The balloon experimental twin telescope for infrared interferometry (BETTII): interferometry at the edge of the atmosphere

    NASA Astrophysics Data System (ADS)

    Rinehart, S.; Rizzo, M.; Fixsen, D.; Ade, P.; Barclay, R.; Barry, R.; Benford, D.; Dhabal, A.; Juanola-Parramon, R.; Klemencic, Georgina; Griffin, M.; Leisawitz, David T.; Maher, S.; Mentzell, J.; Mundy, Lee G.; Pascale, E.; Savini, G.; Silverberg, Robert F.; Staguhn, J.; Veach, T.

    2014-07-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer to simultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. This program started in 2011, and is now in the process of building and testing components of the mission, aiming for first flight in fall of 2015. This paper will provide an overview of the BETTII experiment, with a discussion of current progress and of future plans.

  1. Patients' recollections of experiences in the intensive care unit may affect their quality of life

    PubMed Central

    Granja, Cristina; Lopes, Alice; Moreira, Sara; Dias, Claudia; Costa-Pereira, Altamiro; Carneiro, António

    2005-01-01

    Introduction We wished to obtain the experiences felt by patients during their ICU stay using an original questionnaire and to correlate the memories of those experiences with health-related quality of life (HR-QOL). Methods We conducted a prospective study in 10 Portuguese intensive care units (ICUs). Six months after ICU discharge, an original questionnaire on experiences of patients during their ICU stay, the recollection questionnaire, was delivered. HR-QOL was evaluated simultaneously, with the EQ-5D questionnaire. Between 1 September 2002 and 31 March 2003 1433 adult patients were admitted. ICU and hospital mortalities were 21% and 28%, respectively. Six months after ICU discharge, 464 patients completed the recollection questionnaire. Results Thirty-eight percent of the patients stated they did not remember any moment of their ICU stay. The ICU environment was described as friendly and calm by 93% of the patients. Sleep was described as being good and enough by 73%. The experiences reported as being more stressful were tracheal tube aspiration (81%), nose tube (75%), family worries (71%) and pain (64%). Of respondents, 51% experienced dreams and nightmares during their ICU stay; of these, 14% stated that those dreams and nightmares disturb their present daily life and they exhibit a worse HR-QOL. Forty-one percent of patients reported current sleep disturbances, 38% difficulties in concentrating in current daily activities and 36% difficulties in remembering recent events. More than half of the patients reported more fatigue than before the ICU stay. Multiple and linear regression analysis showed that older age, longer ICU stay, higher Simplified Acute Physiology Score II, non-scheduled surgery and multiple trauma diagnostic categories, present sleep disturbances, daily disturbances by dreams and nightmares, difficulties in concentrating and difficulties in remembering recent events were independent predictors of worse HR-QOL. Multicollinearity analysis

  2. CAREGIVERS OF THE CHRONICALLY CRITICALLY ILL AFTER DISCHARGE FROM THE INTENSIVE CARE UNIT: SIX MONTHS’ EXPERIENCE

    PubMed Central

    Choi, JiYeon; Donahoe, Michael P.; Zullo, Thomas G.; Hoffman, Leslie A.

    2011-01-01

    Background Chronically critically ill patients typically undergo an extended recovery after discharge from the intensive care unit, making involvement of family caregivers essential. Prior studies provide limited detail about specific ways this experience affects caregivers. Objectives To (1) describe lifestyle restrictions and distress among caregivers of chronically critically ill patients 1 and 6 months after discharge and (2) explore how caregivers’ lifestyle restrictions and distress differ according to patients’ and caregivers’ characteristics. Methods Sixty-nine chronically critically ill patients and their family caregivers completed follow-up at 1 and 6 months after discharge from the intensive care unit. Data were collected from medical records and survey via telephone or mail. Results Caregivers’ perceived lifestyle restrictions (Changes in Role Function) decreased from 1 month (mean [SD], 23.0 [8.3]) to 6 months (19.4 [8.6]) after discharge (P = .003), although patients’ problem behaviors and caregivers’ distress (8.9 [9.3] vs 7.9 [9.6], respectively; P = .32) did not change. Change in caregivers’ lifestyle restrictions differed by patients’ disposition (P = .02) and functional status (Health Assessment Questionnaire; P = .007). Caregiver’s lifestyle restrictions remained high when patients never returned home or never recovered their preadmission functional status. Caregivers reported the most restrictions in social life and personal recreation. Patients’ negative emotions and pain caused the most caregiver distress. Conclusions Caregivers of chronically critically ill patients perceived fewer lifestyle restrictions over time but reported no change in patients’ problem behaviors or distress. Lifestyle restrictions and distress remained high when patients never returned home or regained their preadmission functional status. PMID:21196567

  3. Novel characterization of the nonlinear refractive response of materials using spatially and spectrally resolved interferometry

    NASA Astrophysics Data System (ADS)

    Meier, Amanda; Adams, Daniel; Squier, Jeff; Durfee, Charles

    2010-10-01

    Characterization of the nonlinear refractive index of a material is important in order to fully understand the nonlinear propagation of femtosecond laser pulses. The most common method to obtaining the nonlinear refractive index is Z-scan. However, since it averages over pulse duration and beam profile, Z-scan is not reliable when there is time- and intensity-dependence of the nonlinear response. The new method we are exploring to make these nonlinear refractive index measurements is spatially and spectrally resolved interferometry (SSRI). SSRI is a method that can give a simultaneous measurement of the spatial wave-front across the frequency or temporal profile of the pulse. The SSRI method proves better in measuring response at specific y and t, allowing it to measure both delayed response and saturation effects. The ability to make a measurement in both dimensions enables understanding of spatiotemporal dynamics in other experiments as cross-wave polarization and filamentation.

  4. Inside the research incubator: a case study of an intensive undergraduate research experience for nursing a midwifery students.

    PubMed

    Kain, Victoria J; Hepworth, Julie; Bogossian, Fiona; McTaggart, Lya

    2014-01-01

    Undergraduate research experiences are an increasing component of nursing and midwifery degrees. The Summer Research Scholarship Programme (SRSP) is a tertiary education initiative in Australia to provide an intensive undergraduate research experience. Between 2009 and 2010, six students and four academic faculty mentors in School of Nursing and Midwifery participated in an inaugural SRSP. This study explores the experiences of both students and faculty mentors to determine how this undergraduate research experience impacted student learning and interest in research. A qualitative case study approach was used to explore the research experiences of undergraduate student and faculty participants in an inaugural undergraduate research programme. Based on the results of two surveys four main themes were identified: (1) acquisition of research skills, (2) expectations, (3) academic engagement, and (4) continued interest in research. An intensive undergraduate research experience is a valuable component of student learning that has the capacity to contribute to immediate and longer-term learning and research outcomes.

  5. Neutron interferometry: The pioneering contributions of Samuel A. Werner

    NASA Astrophysics Data System (ADS)

    Klein, A. G.

    2006-11-01

    In 1975, Sam Werner, while on the staff of the Scientific Laboratory of the Ford Motor Company, and his collaborators from Purdue University, Roberto Colella and Albert Overhauser, carried out one of the pioneering experiments in neutron interferometry at the 2 MW University of Michigan research reactor. It was the famous COW Experiment [Colella et al., Phys. Rev. Lett. 34 (1975) 1472] on gravitationally induced quantum interference. Shortly thereafter he moved to the University of Missouri in Columbia, to set up a program of neutron scattering research, including neutron interferometry. In the 25 years until his retirement a large number of beautiful experiments have been performed by Sam, with his group, his numerous students and many international collaborators. This work and its history are briefly reviewed in this paper.

  6. Remote monitoring of the earthquake cycle using satellite radar interferometry.

    PubMed

    Wright, Tim J

    2002-12-15

    The earthquake cycle is poorly understood. Earthquakes continue to occur on previously unrecognized faults. Earthquake prediction seems impossible. These remain the facts despite nearly 100 years of intensive study since the earthquake cycle was first conceptualized. Using data acquired from satellites in orbit 800 km above the Earth, a new technique, radar interferometry (InSAR), has the potential to solve these problems. For the first time, detailed maps of the warping of the Earth's surface during the earthquake cycle can be obtained with a spatial resolution of a few tens of metres and a precision of a few millimetres. InSAR does not need equipment on the ground or expensive field campaigns, so it can gather crucial data on earthquakes and the seismic cycle from some of the remotest areas of the planet. In this article, I review some of the remarkable observations of the earthquake cycle already made using radar interferometry and speculate on breakthroughs that are tantalizingly close.

  7. End-of-life care in the neonatal intensive care unit: experiences of staff and parents.

    PubMed

    Cortezzo, DonnaMaria E; Sanders, Marilyn R; Brownell, Elizabeth A; Moss, Kerry

    2015-07-01

    The aim of the study is to determine the perceptions of end-of-life care practices and experience with infants who have died in the NICU among neonatologists, advanced practitioners, nurses, and parents, and also to determine perceived areas for improvement and the perceived value of a palliative care team. This descriptive, exploratory cross-sectional study using surveys consisting of 7-point Likert scales and free response comments was sent to all neonatologists (n = 14), advanced practitioners (n = 40), and nurses (n = 184) at Connecticut Children's Medical Center's neonatal intensive care units (NICUs) in April 2013 and to all parents whose infants died in these NICUs from July 1, 2011, to December 31, 2012 (n = 28). The response rates were 64.3% for physicians; 50.0% for practitioners; 40.8% for nurses; and 30.4% for parents. Most providers reported they feel comfortable delivering end-of-life care. Bereavement support, debriefing/closure conferences, and education did not occur routinely. Families stressed the importance of memory making and bereavement/follow-up. Consistent themes of free responses include modalities for improving end-of-life care, inconsistency of care delivery among providers, and the importance of memory making and follow-up. End-of-life experiences in the NICU were perceived as variable and end-of-life practices were, at times, perceived as inconsistent among providers. There are areas for improvement, and participants reported that a formalized palliative care team could help. Families desire memory making, follow-up, and bereavement support. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Swiss Experiment: Design, implemention and use of a cross-disciplinary infrastructure for data intensive science

    NASA Astrophysics Data System (ADS)

    Dawes, N.; Salehi, A.; Clifton, A.; Bavay, M.; Aberer, K.; Parlange, M. B.; Lehning, M.

    2010-12-01

    It has long been known that environmental processes are cross-disciplinary, but data has continued to be acquired and held for a single purpose. Swiss Experiment is a rapidly evolving cross-disciplinary, distributed sensor data infrastructure, where tools for the environmental science community stem directly from computer science research. The platform uses the bleeding edge of computer science to acquire, store and distribute data and metadata from all environmental science disciplines at a variety of temporal and spatial resolutions. SwissEx is simultaneously developing new technologies to allow low cost, high spatial and temporal resolution measurements such that small areas can be intensely monitored. This data is then combined with existing widespread, low density measurements in the cross-disciplinary platform to provide well documented datasets, which are of use to multiple research disciplines. We present a flexible, generic infrastructure at an advanced stage of development. The infrastructure makes the most of Web 2.0 technologies for a collaborative working environment and as a user interface for a metadata database. This environment is already closely integrated with GSN, an open-source database middleware developed under Swiss Experiment for acquisition and storage of generic time-series data (2D and 3D). GSN can be queried directly by common data processing packages and makes data available in real-time to models and 3rd party software interfaces via its web service interface. It also provides real-time push or pull data exchange between instances, a user management system which leaves data owners in charge of their data, advanced real-time processing and much more. The SwissEx interface is increasingly gaining users and supporting environmental science in Switzerland. It is also an integral part of environmental education projects ClimAtscope and O3E, where the technologies can provide rapid feedback of results for children of all ages and where the

  9. Optical and Infrared Interferometry IV

    NASA Astrophysics Data System (ADS)

    Rajagopal, Jayadev K.; Creech-Eakman, Michelle J.; Malbet, Fabien

    2014-08-01

    Optical and IR Interferometry IV at the SPIE 2014 symposium in Montreal had a strong and vibrant program. After initial fears about budget cuts and travel-funding constraints, the Program Committee had to work hard to accommodate as many quality submissions as possible. Innovative, creative and visionary work ensured that the field has progressed well, despite the bleak funding climate felt in the US, Europe and elsewhere. Montreal proved an excellent venue for this, the largest of Interferometry conferences and the only one that brings together practitioners from the world over. Let us summarize a few highlights to convey a glimpse of the excitement that is detailed in the rest of these Proceedings.

  10. Integrated optics for astronomical interferometry

    NASA Astrophysics Data System (ADS)

    Marques, P. V. S.; Ghasempour, A.; Alexandre, D.; Leite, A. M. P.; Garcia, P. J. V.; Reynaud, F.

    2011-05-01

    Integrated optics is a well established technology that finds its main applications in the fields of optical communication and sensing. However, it is expanding into new areas, and in the last decade application in astronomical interferometry has been explored. In particular, several examples have been demonstrated in the areas of beam control and combination. In this paper, different examples of application integrated optics devices for fabrication of beam combiners for astronomical interferometry is given. For the multiaxial beam combiners, a UV laser direct writing unit is used for mask fabrication. The operation principles of the coaxial combiners fabricated in hybrid sol-gel were validated using an interferometric set-up. These results demonstrate that hybrid sol-gel technology can produce quality devices, opening the possibility of rapid prototyping of new designs and concepts.

  11. Treatment of Nasopharyngeal Carcinoma Using Intensity-Modulated Radiotherapy-The National Cancer Centre Singapore Experience

    SciTech Connect

    Tham, Ivan Weng-Keong; Hee, Siew Wan; Yeo, Richard Ming-Chert; Salleh, Patemah; Lee, James; Tan, Terence Wee-Kiat; Fong, Kam Weng; Chua, Eu Tiong; Wee, Joseph Tien-Seng

    2009-12-01

    Purpose: The aim of this study was to determine the efficacy and acute toxicity of our early experience with treating nasopharyngeal carcinoma (NPC) patients with intensity-modulated radiotherapy (IMRT). Methods and materials: A review was conducted on case records of 195 patients with histologically proven, nonmetastatic NPC treated with IMRT between 2002 and 2005. MRI of the head and neck was fused with CT simulation images. All plans had target volumes at three dose levels, with a prescribed dose of 70 Gy to the gross disease, in 2.0-2.12 Gy/fraction over 33-35 fractions. Cisplatin-based chemotherapy was offered to Stage III/IV patients. Results: Median patient age was 52 years, and 69% were male. Median follow-up was 36.5 months. One hundred and twenty-three patients had Stage III/IV disease (63%); 50 (26%) had T4 disease. One hundred and eighty-eight (96%) had complete response; 7 (4%) had partial response. Of the complete responders, 10 (5.3%) had local recurrence, giving a 3-year local recurrence-free survival estimate of 93.1% and a 3-year disease-free survival of 82.1%. Fifty-one patients (26%) had at least one Grade 3 toxicity. Conclusions: Results from our series are comparable to those reported by other centers. Acute toxicity is common. Local failure or persistent disease, especially in patients with bulky T4 disease, are issues that must be addressed in future trials.

  12. [Mothers' experiences and perspectives regarding their premature infant's stay at the neonatal intensive care unit].

    PubMed

    de Araújo, Bárbara Bertolossi Marta; Rodrigues, Benedita Maria Rêgo Deusdará

    2010-12-01

    The purpose of this study was to learn the reason why mothers remain at the hospital throughout the stay of their premature infant at the Neonatal Intensive Care Unit. The study was performed with twelve mothers to premature newborns at a municipal maternity hospital in Rio de Janeiro, in 2007. The methodological support used in the study was the Sociological Phenomenology of Alfred Schütz. The phenomenological interview was used to capture the mothers' discourse, whose intentional action was unveiled through the following categories: Taking care of the child--dealing with the challenge of having a small baby; Staying near the premature child--the mother's presence helps the child's recovery to be faster; Reciprocal help among mothers--reinforcing hope every day. Rooming-in care stands out as an innovative and relevant initiative during the hospital stay of preterm infants, and it is considered an environment for living together, sharing experiences, and giving mutual support throughout the long and difficult stay at the hospital.

  13. Local Scale Radiobrightness Modelling during Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Haoyu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2004-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in the spring of 2003 in Colorado, USA. Initial forward model validation work is concentrating on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. This paper will focus on the ability of forward Dense Medium Radiative Transfer (DMRT) modelling, combined with snowpack measurements to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System at 19 and 37 GHz during the 4th Intensive Observing Period (IOP4) in March, 2003. Unlike the earlier IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. Observations of upwelling and downwelling tree radiobrightness will be used to formulate a simple model for the effect of trees within the field of view. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo s Ground- Based Microwave Radiometer-7 (GBMR-7). These analyses will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  14. Demeter/ICE Experiment: Study of low frequency transmitter intensity variations

    NASA Astrophysics Data System (ADS)

    Boudjada, M. Y.; Moldovan, I.; Schwingenschuh, K.; Al-Haddad, E.; Biagi, P. F.; Parrot, M.

    2012-04-01

    We report on low frequency (LF) transmitter signal recorded by the 'Instrument Capteur Electrique' (ICE) experiment onboard the DEMETER micro-satellite. We mainly consider the signal emitted by the Brasov broadcasting station (25.60E, 45.75N) at frequency of about 153 kHz. We analyze the reception conditions of this transmitter several weeks before the occurrence of the Vrancea earthquakes, on October, 27th, 2004. Ground-based observations revealed the presence of sudden decrease of the Y-component of the magnetic field at Muntele Rosu Observatory (Romania), at about 68 km from the epicenter, as reported by Moldovan et al. (Rom. Journ. Phys., Vol. 54, Nos. 1-2, p. 249-261, Bucharest, 2009). In this contribution we attempt to check if the LF Brasov signal was also subject to similar disturbances as observed by the ground-station. We focus on the variation of the LF transmitter intensity levels, several weeks before and after the Vrancea earthquake occurrence. We discuss the physical parameters which may disturb the signal reception in particular the geomagnetic activity and the signal to noise ratios.

  15. Normal and Differential SAR Interferometry

    DTIC Science & Technology

    2007-02-01

    This Interferogramme is defined as the product of the complex SAR values of the second image with the complex conjugate of the reference image...which is covered by vegetation in the yellow Square. The phase information can be used for Digital Elevation Model (DEM) production , provided the...and X-Band There are a number of causes for de-correlation in Interferometry, and it is possible to write the coherence as a product of factors

  16. White Light Heterodyne Interferometry SNR

    DTIC Science & Technology

    2015-04-09

    INTRODUCTION The subject of heterodyne interferometry, most successfully demonstrated for astronomy in the long- wave infrared (LWIR) at the...zero sun -like star puts out 4 × 107 photons/s/m2/nm at the surface of the earth at this wavelength, which corresponds to a power per unit bandwidth...MID- WAVE AND LONG- WAVE INFRARED While there is a significant penalty to the heterodyne approach in the visible through short- wave infrared (SWIR

  17. Normal and Differential SAR Interferometry

    DTIC Science & Technology

    2005-02-01

    Geudtner, B. Schättler, P. Vachon, U. Steinbrecher, J. Holzner, J. Mittermayer , H. Breit, A. Moreira. RADARSAT ScanSAR interferometry. In: Proceedings of...part 4, pp. 470-475 Krieger, G., Wendler, M., Fiedler, H., Mittermayer , J., Moreira, A., 2002. Performance analysis for bistatic interferometric...SAR configurations. In: Proceedings of IGARSS 2002, Toronto, Canada, vol. 1, pp. 650-652. Krieger, G., Fiedler, H., Mittermayer , J., Papathanassiou, K

  18. Holographic Interferometry The Twentieth Anniversary

    NASA Astrophysics Data System (ADS)

    Pryputniewicz, Ryszard J.

    1985-08-01

    Professor Ryszard Pryputniewicz of Worcester Polytechnic Institute has assembled a significant group of papers on the subject of holographic interferometry in celebration of the first twenty years of activity in this field. Several of these papers were received too late for inclusion in this issue but will be published as a group in the next issue of Optical Engineering. Taken together, these papers are an indication of the tremendous progress made during the twenty years of this field's existence.

  19. Lucky interferometry for displacement measurement

    NASA Astrophysics Data System (ADS)

    Ioniţă, Bogdan; Logofătu, Petre Cătălin; Apostol, Dan

    2009-11-01

    We extrapolated the lucky imaging technique, mostly used in astronomy, to the field of interferometry for displacement measurement. From the batch of interferograms generated by a Twyman-Green-type interferometer and acquired by a CCD camera, those with high overall contrast were selected and fitted to a sinusoidal function. The high-contrast interferograms showed a significantly lower dispersion and, consequently, a lower uncertainty of the measured displacement.

  20. Geometric Landau-Zener interferometry.

    PubMed

    Gasparinetti, S; Solinas, P; Pekola, J P

    2011-11-11

    We propose a new type of interferometry, based on geometric phases accumulated by a periodically driven two-level system undergoing multiple Landau-Zener transitions. As a specific example, we study its implementation in a superconducting charge pump. We find that interference patterns appear as a function of the pumping frequency and the phase bias, and clearly manifest themselves in the pumped charge. We also show that the effects described should persist in the presence of realistic decoherence.

  1. The Keck Aperture Masking Experiment: Spectro-Interferometry of Three Mira Variables from 1.1 to 3.8 μm

    NASA Astrophysics Data System (ADS)

    Woodruff, H. C.; Ireland, M. J.; Tuthill, P. G.; Monnier, J. D.; Bedding, T. R.; Danchi, W. C.; Scholz, M.; Townes, C. H.; Wood, P. R.

    2009-02-01

    We present results from a spectro-interferometric study of the Miras o Cet, R Leo, and W Hya obtained with the Keck Aperture Masking Experiment from 1998 September to 2002 July. The spectrally dispersed visibility data permit fitting with circularly symmetric brightness profiles such as a simple uniform disk (UD). The stellar angular diameter obtained over up to ~ 450 spectral channels spanning the region 1.1-3.8 μm is presented. Use of a simple UD brightness model facilitates comparison between epochs and with existing data and theoretical models. Strong size variations with wavelength were recorded for all stars, probing zones of H2O, CO, OH, and dust formation. Comparison with contemporaneous spectra extracted from our data shows a strong anticorrelation between the observed angular diameter and flux. These variations consolidate the notion of a complex stellar atmosphere consisting of molecular shells with time-dependent densities and temperatures. Our findings are compared with existing data and pulsation models. The models were found to reproduce the functional form of the wavelength versus angular diameter curve well, although some departures are noted in the 2.8-3.5 μm range.

  2. Interferometry of background acoustic-gravity waves

    NASA Astrophysics Data System (ADS)

    Zabotin, Nikolay A.; Godin, Oleg A.; Sheehan, Anne F.

    2013-04-01

    In addition to acoustic-gravity waves generated in the ocean and atmosphere by strong transient events such as earthquakes and tsunamis, there exists a certain background level of acoustic-gravity waves. Because of their large free path length and a wide spatial distribution of the wave sources, background acoustic-gravity waves form a diffuse (but not necessarily isotropic), random wave field. Wave fields generated by uncorrelated sources are known to retain finite correlation at ranges large compared to the wavelength and spatial dimensions of the random wave sources. A technique known as noise (or wave) interferometry has been shown in seismology, helioseismology, acoustics, and other fields to be an effective tool for retrieving information about the deterministic propagation environment and the random wave field from two-point cross-correlation functions of diffuse noise. Here, we apply wave interferometry to acoustic-gravity waves in the coupled ocean-atmosphere system. The primary dataset analyzed in this study was obtained by 30 differential pressure gauges deployed from January 2009 to February 2010 on the seafloor offshore the South Island of New Zealand in the course of the Marine Observations of Anisotropy Near Aotearoa (MOANA) Seismic Experiment [Yang, Z., A. Sheehan, J. A. Collins, and G. Laske (2012), The character of seafloor ambient noise recorded offshore New Zealand: Results from the MOANA ocean bottom seismic experiment, Geochem. Geophys. Geosyst., 13, Q10011]. By applying time-reversal ideas to processing of cross-correlations of random wave fields, we have developed a compressed cross-correlation function technique to compensate for wave dispersion in evaluating the cross-correlation function of a random wave field. When applied to the seafloor pressure data, the technique drastically reduces the signal averaging times necessary for emergence of deterministic features and allows for accurate passive measurements of wave travel times and

  3. Edge effects in composites by moire interferometry

    NASA Technical Reports Server (NTRS)

    Czarnek, R.; Post, D.; Herakovich, C.

    1983-01-01

    The very high sensitivity of moire interferometry has permitted the present edge effect experiments to be conducted at a low average stress and strain level, assuring linear and elastic behavior in the composite material samples tested. Sensitivity corresponding to 2450 line/mm moire was achieved with a 0.408 micron/fringe. Simultaneous observations of the specimen face and edge displacement fields showed good fringe definition despite the 1-mm thickness of the specimens and the high gradients, and it is noted that the use of a carrier pattern and optical filtering was effective in even these conditions. Edge effects and dramatic displacement gradients were confirmed in angle-ply composite laminates.

  4. Edge effects in composites by moire interferometry

    NASA Technical Reports Server (NTRS)

    Czarnek, R.; Post, D.; Herakovich, C.

    1983-01-01

    The very high sensitivity of moire interferometry has permitted the present edge effect experiments to be conducted at a low average stress and strain level, assuring linear and elastic behavior in the composite material samples tested. Sensitivity corresponding to 2450 line/mm moire was achieved with a 0.408 micron/fringe. Simultaneous observations of the specimen face and edge displacement fields showed good fringe definition despite the 1-mm thickness of the specimens and the high gradients, and it is noted that the use of a carrier pattern and optical filtering was effective in even these conditions. Edge effects and dramatic displacement gradients were confirmed in angle-ply composite laminates.

  5. Nanoscale defect detection by heterodyne interferometry

    SciTech Connect

    Lin Haoshan; Li Yuhe; Wang Dongsheng; Tong Xiaolei; Liu Mei

    2009-03-10

    We construct an instrument that facilitates the measurement of nanoscale defects. It is based on heterodyne interferometry with phase measurement that utilizes a polarizing beam splitter to form a measuring signal and an oscillating cantilever tip that acts as a scanning probe to get the measurement values of sample topography. The dependence of the tip displacement on the variation of tip-sample distance and the comb scanning of the sample topography are investigated by experiments. The results prove that the tip displacement increases and is enough to be discriminated in various positions where the sample is approached. The system has been successfully utilized to measure the defect characterization by measuring the pitch of the standard sample. The results also show that the heterodyne system has good repeatability, a large measurement range, and high accuracy, with a measurement stability of 0.5 nm.

  6. Optics and interferometry with atoms and molecules

    SciTech Connect

    Cronin, Alexander D.; Schmiedmayer, Joerg; Pritchard, David E.

    2009-07-15

    Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic clocks. Atom interferometry is now reaching maturity as a powerful art with many applications in modern science. In this review the basic tools for coherent atom optics are described including diffraction by nanostructures and laser light, three-grating interferometers, and double wells on atom chips. Scientific advances in a broad range of fields that have resulted from the application of atom interferometers are reviewed. These are grouped in three categories: (i) fundamental quantum science, (ii) precision metrology, and (iii) atomic and molecular physics. Although some experiments with Bose-Einstein condensates are included, the focus of the review is on linear matter wave optics, i.e., phenomena where each single atom interferes with itself.

  7. Low Coherence Interferometry in Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Neef, A.; Seyda, V.; Herzog, D.; Emmelmann, C.; Schönleber, M.; Kogel-Hollacher, M.

    Selective Laser Melting (SLM) is an additive layer manufacturing technology that offers several advantages compared to conven- tional methods of production such as an increased freedom of design and a toolless production suited for variable lot sizes. Despite these attractive aspects today's state of the art SLM machines lack a holistic process monitoring system that detects and records typical defects during production. A novel sensor concept based on the low coherence interferometry (LCI) was integrated into an SLM production setup. The sensor is mounted coaxially to the processing laser beam and is capable of sampling distances along the optical axis. Measurements during and between the processing of powder layers can reveal crucial topology information which is closely related to the final part quality. The overall potential of the sensor in terms of quality assurance and process control is being discussed. Furthermore fundamental experiments were performed to derive the performance of the system.

  8. Analytical model for calibrating laser intensity in strong-field-ionization experiments

    NASA Astrophysics Data System (ADS)

    Zhao, Song-Feng; Le, Anh-Thu; Jin, Cheng; Wang, Xu; Lin, C. D.

    2016-02-01

    The interaction of an intense laser pulse with atoms and molecules depends extremely nonlinearly on the laser intensity. Yet experimentally there still exists no simple reliable methods for determining the peak laser intensity within the focused volume. Here we present a simple method, based on an improved Perelomov-Popov-Terent'ev model, that would allow the calibration of laser intensities from the measured ionization signals of atoms or molecules. The model is first examined by comparing ionization probabilities (or signals) of atoms and several simple diatomic molecules with those from solving the time-dependent Schrödinger equation. We then show the possibility of using this method to calibrate laser intensities for atoms, diatomic molecules as well as large polyatomic molecules, for laser intensities from the multiphoton ionization to tunneling ionization regimes.

  9. Plasmonic interferometry: Probing launching dipoles in scanning-probe plasmonics

    NASA Astrophysics Data System (ADS)

    Mollet, Oriane; Bachelier, Guillaume; Genet, Cyriaque; Huant, Serge; Drezet, Aurélien

    2014-03-01

    We develop a semi-analytical method for analyzing surface plasmon interferometry using scanning-probe tips as SP launchers. We apply our approach to Young double-hole interferometry experiments in a scanning tunneling microscope discussed recently in the literature as well as to new experiments—reported here—with an aperture near-field scanning optical microscope source positioned near a ring-like aperture slit in a thick gold film. In both experimental configurations, the agreement between experiments and model is very good. Our work reveals the role of the launching dipole orientations and magnetic versus electric dipole contributions to the interference imaging process. It also stresses the different orientations of the effective dipoles associated with the two different scanning-probe techniques.

  10. Observation of Aharonov-Bohm effects by neutron interferometry

    NASA Astrophysics Data System (ADS)

    Werner, Samuel A.; Klein, Anthony G.

    2010-09-01

    The special and unique techniques of neutron interferometry have been used to observe a number of topological effects. These include the quantum mechanical phase shift of a neutron due to the Earth's rotation (the quantum analog of the Michelson-Gale-Pearson experiment with light), the phase shift of a particle carrying a magnetic moment (a neutron) encircling a line charge (the Aharonov-Casher effect) and the scalar Aharonov-Bohm effect, observed with a pulsed magnetic field solenoid and time-of-flight neutron detection. On the occasion of the 50th anniversary of the Aharonov-Bohm paper, we provide an overview of the neutron interferometry technique and a description of these three historic experiments.

  11. Very long baseline interferometry using a communication satellite

    NASA Technical Reports Server (NTRS)

    Swenson, G. W., Jr.

    1975-01-01

    A planned experiment is discussed in long-baseline interferometry, using the Communications Technology Satellite to transmit the base-band signal from one telescope to another for real-time correlation. A 20 megabit data rate is planned, calling for a delay-line of 10 MHz bandwidth and controllable delay up to 275 milliseconds. A number of sources will be studied on baselines from Ontario to West Virginia and California.

  12. Precision Measurement of the Newtonian Gravitational Constant by Atom Interferometry

    NASA Astrophysics Data System (ADS)

    Rosi, G.; D'Amico, G.; Tino, G. M.; Cacciapuoti, L.; Prevedelli, M.; Sorrentino, F.

    We report on the latest determination of the Newtonian gravitational constant G using our atom interferometry gravity gradiometer. After a short introduction on the G measurement issue we will provide a description of the experimental method employed, followed by a discussion of the experimental results in terms of sensitivity and systematic effects. Finally, prospects for future cold atom-based experiments devoted to the measurement of this fundamental constant are reported.

  13. Using Atom Interferometry to Search for New Forces

    SciTech Connect

    Wacker, Jay G.; /SLAC

    2009-12-11

    Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10{sup 2} and near-future advances will be able to rewrite the limits for forces with ranges from 100 {micro}m to 1km.

  14. Eutrophication and algal blooms in channel type reservoirs: a novel enclosure experiment by changing light intensity.

    PubMed

    Cao, Chengjin; Zheng, Binghui; Chen, Zhenlou; Huang, Minsheng; Zhang, Jialei

    2011-01-01

    To explore eutrophication and algal bloom mechanisms in channel type reservoirs, a novel enclosure experiment was conducted by changing light intensity (LI) in the Daning River of the Three Gorges Reservoir (TGR). Square enclosures (side 5.0 m) were covered on the surface with shading materials of different thickness, and with their bases open to the river. Changes and characteristics of the main eutrophication factors under the same water quality and hydrodynamic conditions but different LI were evaluated. All experimental water samples were neutral and alkalescent, with high nitrogen and phosphate concentrations, low potassium permanganate index, stable water quality, and different LI. At the same water depth, LI decreased with increasing shade material, while dissolved oxygen and water temperature were both stable. The growth peak of phytoplankton was with light of 345-4390 lux underwater or 558-7450 lux above the water surface, and water temperature of 25.6-26.5 degrees C. Algae were observed in all water samples, accounting for 6 phylum and 57 species, with algal density changing frequently. The results showed that significantly strong or weak light was unfavorable for phytoplankton growth and the function together with suitable temperature and LI and ample sunshine encouraged algal blooms under the same water quality and hydrodynamic conditions. Correlation analysis indicated that algae reduced gradually lengthwise along water depth in the same enclosure while pH became high. The power exponent relationship between chlorophyll a (Chl-a) and LI was found by curve fitting, that is Chl-a = K(LI)(n).

  15. An integrated ultrasound-guided high intensity focused ultrasound system for in-vivo experiment

    NASA Astrophysics Data System (ADS)

    Liu, Dalong; Ebbini, Emad S.

    2017-03-01

    We present the system architecture of an integrated Ultrasound-guided High Intensity Focused Ultrasound (USgHIFU) system for image-guided surgery and temperature tracking in vivo. The system is capable of operating with multiple frontends. Current implementation has a SonixRP for imaging and a custom designed dual mode ultrasound array (DMUA) system (32Tx/32Rx) for imaging/therapy. The highlights of the system include a fully-programmable, multiple data stream capable data processing engine, and an arbitrarily programmable high power array driver that is able to synthesize complex beam patterns in space and time. The data processing engine features a pipeline-style design that can be programmed on-the-fly by re-arranging the pre-verified GPU-accelerated high performance pipeline blocks, which cover an extensive range from basic functions such as filtering to specialized processing like speckle tracking. Furthermore, the pipeline design also has the option of bringing in MATLAB (Mathworks, Natick, MA, US) as part of the processing chain, thus vastly increase the capability of the system. By properly balancing the processing load between GPU-enabled routine and MATLAB script. This allows one to achieve a high degree of flexibility while meeting real-time constraints. Results are presented from in vivo rat experiment. Where low dose of therapeutic ultrasound was delivered into the hind limb of the Copenhagen rats using DMUA and temperature was tracked using a linear probe (HST, Ultrasonix). The data is processed in realtime with MATLAB in the loop to perform temperature regularization. Results show that we can reliably track the low temperature heating in the presence of motion artifacts (respiration and pulsation).

  16. Drivers of choice of resuscitation fluid in the intensive care unit: a discrete choice experiment.

    PubMed

    Taylor, Colman B; Hammond, Naomi E; Laba, Tracey-Lea; Watts, Nicola; Thompson, Kelly; Saxena, Manoj; Micallef, Sharon; Finfer, Simon; Myburgh, John

    2017-06-01

    To understand the fundamental drivers, and their relative importance, of doctors' and nurses' choice of resuscitation fluid in critically ill patients in Australia and New Zealand. A discrete choice experiment (DCE) administered via an online survey. Respondents were presented with one of four randomly selected DCE choice sets, each including five patient scenarios. The respondent chose between two types of hypothetical resuscitation fluid. The fluid type was characterised by several attributes and each attribute had pre-specified levels. Convenience sample of 367 Australian and New Zealand intensive care unit doctors and nurses. The dependent variable was fluid choice, and a regression equation was used to estimate the effect of each fluid attribute on the probability of observing the sequence of choices made over the five patient scenarios. The relative importance of each of the respective fluid attributes was calculated based on the percentage contribution to overall utility (ie, fluid preference). For doctors, safety concerns, patient type and fluid type were collectively responsible for almost three-quarters of decision-making utility (71%). The volume of intravenous fluid administered was the only clinical parameter not reaching statistical significance as a driver of fluid choice (P = 0.06). For nurses, decision making was influenced to a greater extent by the same three attributes (90%), although other unmeasured attributes may have been driving choice. Doctors and nurses rely on different information when choosing resuscitation fluids, although both cohorts are heavily influenced by safety concerns, patient type and fluid type. This information can be used to modify prescribing behaviour.

  17. Experience with Guillain-Barré syndrome in a neurological Intensive Care Unit.

    PubMed

    González, P; García, X; Guerra, A; Arango, J C; Delgado, H; Uribe, C S; Sará, J; López de Mesa, J C; Hernández, O

    2016-01-01

    Guillain-Barré syndrome, an acute polyradiculoneuropathy that presents with weakness and areflexia, is the most common cause of acute flaccid paralysis. In certain patients, respiratory failure is secondary to this disorder, eventually causing patients to require mechanical ventilation and experience additional complications due to diminished respiratory support and related mobility limitations. Prognoses for most of these cases are positive; treatment consists of basic support combined with plasmapheresis or administration of immunoglobulins. This study sought to describe the socio-demographic, clinical, laboratory and neurophysiological characteristics of patients with Guillain-Barré syndrome who were hospitalised in the Intensive Care Unit of the Neurological Institute of Colombia between 2006 and 2012. This study presents a case series. We surveyed 25 patients (32% female and 68% male) with Guillain-Barré syndrome and an average age of 54 years. Sixty per cent of these patients were admitted between days 3 and 7 after symptom onset; 64% had a history of respiratory infection and 20% had a history of intestinal infection. In addition, 84% of the patients presented with albuminocytological dissociation. We observed the following clinical subtypes of Guillain-Barré syndrome: inflammatory demyelinating polyneuropathy in 32%, acute motor-sensory axonal neuropathy in 28%, acute motor axonal neuropathy in 28%, and Miller Fisher syndrome in 12%. In this descriptive study of a group of critical care patients with GBS, results depended on patients' clinical severity at time of admission. Our findings are similar to results published in the international literature. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Monitoring grazing intensity: an experiment with canopy spectra applied to satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Li, Fei; Zhao, Ying; Zheng, Jiajia; Luo, Juhua; Zhang, Xiaoqiang

    2016-04-01

    The quantification of grassland grazing intensity (GI) and its detailed spatial distribution are important for grassland management and ecological protection. Remote sensing has great potential in these areas, but its use is still limited. This study analyzed the impacts of grazing on biophysical properties of vegetation and suggested using biomass to quantify GI because of its stability and interpretability. In comparison to a single spectral index, such as the red edge index (REI), combining REI and a cellulose absorption ratio index calculated from hyperspectral data performs better for biomass estimation. Further, an auxiliary spectral index, called the grazing monitoring index (GMI), was developed based on differences in spectral reflectance in the infrared range. Experiments in a grazing area of the Inner Mongolia grassland indicated that GMI can identify GI, with three range intervals (GMI <0, 0-1, and ≥1) used to describe the biomass distribution. The results showed that combining GMI and biomass was more successful than existing approaches for identifying the grassland variability resulting from the spatial heterogeneity of grazing behavior. The thresholds of biomass for four GI levels (ungrazed, lightly grazed, moderately grazed, and heavily grazed) could be determined by the intersections of biomass distributions. In addition, the approach developed at the on-ground canopy scale was extended to remotely sensed Hyperion data. The results showed that the approach could successfully identify the grazing treatments of blocks in the experimental grazing area. Overall, our study provides inspiration and ideas for using satellite remote sensing for evaluating plant production, standing biomass, and livestock impacts.

  19. Taking care of the newborn dying and their families: Nurses' experiences of neonatal intensive care.

    PubMed

    Almeida, Fabiane de Amorim; Moraes, Mariana Salim de; Cunha, Mariana Lucas da Rocha

    2016-06-01

    To understand the experiences of nurses when caring for dying newborns and their families in the NICU; and redeem their perceptions about acting before the death and grieving process. A descriptive exploratory study with a qualitative approach, developed with nine nurses at the ICU of a hospital in São Paulo (SP), Brazil. Data was collected through semi-structured interviews and analyzed using the Collective Subject Discourse (CSD). Caring for newborns who are dying and their families is very difficult for nurses, due to the intense involvement. They seek strategies to deal with the situation and, before the newborn's death, despite the suffering, express the feeling of accomplishment. Facing death and grief triggers mechanisms that emerge life references, coming across painful issues. Learning to deal with these questions is a daily challenge for nurses of the NICU. Compreender as experiências vivenciadas por enfermeiros ao cuidar de neonatos que estão morrendo e seus familiares na UTIN; e resgatar as suas percepções sobre a atuação diante do processo de morte e luto. Estudo descritivo exploratório, de abordagem qualitativa, desenvolvido com nove enfermeiras da UTIN de um hospital de São Paulo (SP), Brasil. Os dados foram coletados por meio de entrevista semi-estruturada e analisados pela técnica do Discurso de Sujeito Coletivo (DSC). Cuidar de neonatos que estão morrendo e suas famílias é muito difícil para as enfermeiras, devido ao intenso envolvimento. Buscam estratégias para lidar com a situação e, diante do óbito do neonato, apesar do sofrimento, manifestam o sentimento de dever cumprido. Enfrentar a morte e o luto aciona mecanismos que afloram referências de vida, deparando-se com questões dolorosas. Aprender a lidar com essas questões é um desafio diário para os enfermeiros de UTIN.

  20. Monitoring gas reservoirs by seismic interferometry

    NASA Astrophysics Data System (ADS)

    Grigoli, Francesco; Cesca, Simone; Sens-Schoenfelder, Christoph; Priolo, Enrico

    2014-05-01

    Ambient seismic noise can be used to image spatial anomalies in the subsurface, without the need of recordings from seismic sources, such as earthquakes or explosions. Furthermore, the temporal variation of ambient seismic noise's can be used to infer temporal changes of the seismic velocities in the investigated medium. Such temporal variations can reflect changes of several physical properties/conditions in the medium. For example, they may be consequence of stress changes, variation of hydrogeological parameters, pore pressure and saturation changes due to fluid injection or extraction. Passive image interferometry allows to continuously monitor small temporal changes of seismic velocities in the subsurface, making it a suitable tool to monitor time-variant systems such as oil and gas reservoirs or volcanic environments. The technique does not require recordings from seismic sources in the classical sense, but is based on the processing of noise records. Moreover, it requires only data from one or two seismic stations, their locations constraining the sampled target area. Here we apply passive image interferometry to monitor a gas storage reservoir in northern Italy. The Collalto field (Northern Italy) is a depleted gas reservoir located at 1500 m depth, now used as a gas storage facility. The reservoir experience a significant temporal variation in the amount of stored gas: the injection phases mainly occur in the summer, while the extraction take place mostly in winter. In order to monitor induced seismicity related to gas storage operations, a seismic network (the Collalto Seismic Network) has been deployed in 2011. The Collalto Seismic Network is composed by 10 broadband stations, deployed within an area of about 20 km x 20 km, and provides high-quality continuous data since January 1st, 2012. In this work we present preliminary results from ambient noise interferometry using a two-months sample of continuous seismic data, i.e. from October 1st, 2012, to the

  1. Chameleon dark energy and atom interferometry

    NASA Astrophysics Data System (ADS)

    Elder, Benjamin; Khoury, Justin; Haslinger, Philipp; Jaffe, Matt; Müller, Holger; Hamilton, Paul

    2016-08-01

    Atom interferometry experiments are searching for evidence of chameleon scalar fields with ever-increasing precision. As experiments become more precise, so too must theoretical predictions. Previous work has made numerous approximations to simplify the calculation, which in general requires solving a three-dimensional nonlinear partial differential equation. This paper calculates the chameleonic force using a numerical relaxation scheme on a uniform grid. This technique is more general than previous work, which assumed spherical symmetry to reduce the partial differential equation to a one-dimensional ordinary differential equation. We examine the effects of approximations made in previous efforts on this subject and calculate the chameleonic force in a setup that closely mimics the recent experiment of Hamilton et al. Specifically, we simulate the vacuum chamber as a cylinder with dimensions matching those of the experiment, taking into account the backreaction of the source mass, its offset from the center, and the effects of the chamber walls. Remarkably, the acceleration on a test atomic particle is found to differ by only 20% from the approximate analytical treatment. These results allow us to place rigorous constraints on the parameter space of chameleon field theories, although ultimately the constraint we find is the same as the one we reported in Hamilton et al. because we had slightly underestimated the size of the vacuum chamber. This computational technique will continue to be useful as experiments become even more precise and will also be a valuable tool in optimizing future searches for chameleon fields and related theories.

  2. A qualitative study exploring the experiences of parents of children admitted to seven Dutch pediatric intensive care units

    PubMed Central

    van Goudoever, Johannes B.; Schuurman, Beatrix Elink; Albers, Marcel J. I. J.; van Dam, Nicolette A. M.; Dullaart, Eugenie; van Heerde, Marc; Verlaat, Carin W. M.; van Vught, Elise M.; Hazelzet, Jan A.

    2010-01-01

    Purpose To explore parents' experiences during the admission of their children to a pediatric intensive care unit (PICU). Method Qualitative method using in-depth interviews. Thematic analysis was applied to capture parents’ experiences. Thirty-nine mothers and 25 fathers of 41 children admitted to seven of the eight PICUs in university medical centers in The Netherlands were interviewed. Results Parents were interviewed within 1 month after their child’s discharge from a PICU. Thematic analysis identified 1,514 quotations that were coded into 63 subthemes. The subthemes were categorized into six major themes: attitude of the professionals; coordination of care; emotional intensity; information management; environmental factors; parent participation. Most themes had an overarching relationship representing the array of experiences encountered by parents when their child was staying in a PICU. The theme of emotional intensity was in particular associated with all the other themes. Conclusions The findings provided a range of themes and subthemes describing the complexity of the parental experiences of a PICU admission. The subthemes present a systematic and thematic basis for the development of a quantitative instrument to measure parental experiences and satisfaction with care. The findings of this study have important clinical implications related to the deeper understanding of parental experiences and improving family-centered care. Electronic supplementary material The online version of this article (doi:10.1007/s00134-010-2074-3) contains supplementary material, which is available to authorized users. PMID:21063674

  3. Iterative reconstruction of digital holograms from three intensity measurements

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Wu, Yang; Kelly, Damien P.; Sheridan, John T.

    2016-03-01

    A practical technique is presented based on DH, for the reconstruction of a wavefront from three recorded intensity images. Combining the off-axis Fourier spatial filtering (OFSF) technique with iterative phase retrieval algorithms, it is shown how the twin image can be eliminated. The proposed method overcomes system geometry constraints and improves both the flexibility and resolution associated with OFSF-based DH. It also overcomes the cost problem associated with phase-shifting interferometry-based DH. In order to demonstrate the performance of the proposed DH method, both simulation and experiment results for objects having smooth and rough surfaces are presented.

  4. Holographic Interferometry--A Laboratory Experiment.

    ERIC Educational Resources Information Center

    de Frutos, A. M.; de la Rosa, M. I.

    1988-01-01

    Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

  5. Holographic Interferometry--A Laboratory Experiment.

    ERIC Educational Resources Information Center

    de Frutos, A. M.; de la Rosa, M. I.

    1988-01-01

    Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

  6. Progress in interferometry for LISA at JPL

    NASA Astrophysics Data System (ADS)

    Spero, Robert; Bachman, Brian; de Vine, Glenn; Dickson, Jeffrey; Klipstein, William; Ozawa, Tetsuo; McKenzie, Kirk; Shaddock, Daniel; Robison, David; Sutton, Andrew; Ware, Brent

    2011-05-01

    Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of time delay interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.

  7. Astronomical imaging by pupil plane interferometry

    NASA Technical Reports Server (NTRS)

    Ribak, Erez

    1989-01-01

    Comparing rotational shear interferometry to standard speckle interferometry, it is found that it is easier in the first case to separate the atmospheric phases from the object transform phases. Phase closure and blind deconvolution should be directly applicable. Laboratory simulations were conducted to verify theoretical predictions and computer simulations for the phase closure case, and preliminary results show promise.

  8. Absolute distance interferometry using diode lasers

    NASA Astrophysics Data System (ADS)

    Meiners-Hagen, K.; Abou-Zeid, A.; Hartmann, L.

    2008-10-01

    An approach to a homodyne absolute distance interferometer (ADI) was previously presented which makes use of two extended cavity diode lasers (ECDL). The length measurement is performed by combining variable synthetic wavelength interferometry and two wavelength interferometry in one setup. In this contribution the ADI was compared to a counting HeNe laser interferometer up to a length of 10 m.

  9. Intensive care unit admission of obstetric cases: a single centre experience with contemporary update.

    PubMed

    Ng, Vivian K S; Lo, T K; Tsang, H H; Lau, W L; Leung, W C

    2014-02-01

    OBJECTIVES. To review the characteristics of a series of obstetric patients admitted to the intensive care unit in a regional hospital in 2006-2010, to compare them with those of a similar series reported from the same hospital in 1989-1995 and a series reported from another regional hospital in 1998-2007. DESIGN. Retrospective case series. SETTING. A regional hospital in Hong Kong. PATIENTS. Obstetric patients admitted to the Intensive Care Unit of Kwong Wah Hospital from 1 January 2006 to 31 December 2010. RESULTS. From 2006 to 2010, there were 67 such patients admitted to the intensive care unit (0.23% of total maternities and 2.34% of total intensive care unit admission), which was a higher incidence than reported in two other local studies. As in the latter studies, the majority were admitted postpartum (n=65, 97%), with postpartum haemorrhage (n=39, 58%) being the commonest cause followed by pre-eclampsia/eclampsia (n=17, 25%). In the current study, significantly more patients had had elective caesarean sections for placenta praevia but fewer had had a hysterectomy. The duration of intensive care unit stay was shorter (mean, 1.8 days) with fewer invasive procedures performed than in the two previous studies, but maternal and neonatal mortality was similar (3% and 6%, respectively). CONCLUSION. Postpartum haemorrhage and pregnancy-induced hypertension were still the most common reasons for intensive care unit admission. There was an increasing trend of intensive care unit admissions following elective caesarean section for placenta praevia and for early aggressive intervention of pre-eclampsia. Maternal mortality remained low but had not decreased. The intensive care unit admission rate by itself might not be a helpful indicator of obstetric performance.

  10. TDRS orbit determination by radio interferometry

    NASA Technical Reports Server (NTRS)

    Pavloff, Michael S.

    1994-01-01

    In support of a NASA study on the application of radio interferometry to satellite orbit determination, MITRE developed a simulation tool for assessing interferometry tracking accuracy. The Orbit Determination Accuracy Estimator (ODAE) models the general batch maximum likelihood orbit determination algorithms of the Goddard Trajectory Determination System (GTDS) with the group and phase delay measurements from radio interferometry. ODAE models the statistical properties of tracking error sources, including inherent observable imprecision, atmospheric delays, clock offsets, station location uncertainty, and measurement biases, and through Monte Carlo simulation, ODAE calculates the statistical properties of errors in the predicted satellites state vector. This paper presents results from ODAE application to orbit determination of the Tracking and Data Relay Satellite (TDRS) by radio interferometry. Conclusions about optimal ground station locations for interferometric tracking of TDRS are presented, along with a discussion of operational advantages of radio interferometry.

  11. Experience-Based Quality Control of Clinical Intensity-Modulated Radiotherapy Planning

    SciTech Connect

    Moore, Kevin L.; Brame, R. Scott; Low, Daniel A.; Mutic, Sasa

    2011-10-01

    Purpose: To incorporate a quality control tool, according to previous planning experience and patient-specific anatomic information, into the intensity-modulated radiotherapy (IMRT) plan generation process and to determine whether the tool improved treatment plan quality. Methods and Materials: A retrospective study of 42 IMRT plans demonstrated a correlation between the fraction of organs at risk (OARs) overlapping the planning target volume and the mean dose. This yielded a model, predicted dose = prescription dose (0.2 + 0.8 [1 - exp(-3 overlapping planning target volume/volume of OAR)]), that predicted the achievable mean doses according to the planning target volume overlap/volume of OAR and the prescription dose. The model was incorporated into the planning process by way of a user-executable script that reported the predicted dose for any OAR. The script was introduced to clinicians engaged in IMRT planning and deployed thereafter. The script's effect was evaluated by tracking {delta} = (mean dose-predicted dose)/predicted dose, the fraction by which the mean dose exceeded the model. Results: All OARs under investigation (rectum and bladder in prostate cancer; parotid glands, esophagus, and larynx in head-and-neck cancer) exhibited both smaller {delta} and reduced variability after script implementation. These effects were substantial for the parotid glands, for which the previous {delta} = 0.28 {+-} 0.24 was reduced to {delta} = 0.13 {+-} 0.10. The clinical relevance was most evident in the subset of cases in which the parotid glands were potentially salvageable (predicted dose <30 Gy). Before script implementation, an average of 30.1 Gy was delivered to the salvageable cases, with an average predicted dose of 20.3 Gy. After implementation, an average of 18.7 Gy was delivered to salvageable cases, with an average predicted dose of 17.2 Gy. In the prostate cases, the rectum model excess was reduced from {delta} = 0.28 {+-} 0.20 to {delta} = 0.07 {+-} 0

  12. An Interferometry Imaging Beauty Contest

    NASA Technical Reports Server (NTRS)

    Lawson, Peter R.; Cotton, William D.; Hummel, Christian A.; Monnier, John D.; Zhaod, Ming; Young, John S.; Thorsteinsson, Hrobjartur; Meimon, Serge C.; Mugnier, Laurent; LeBesnerais, Guy; Thiebaut, Eric; Tuthill, Peter G.; Hani, Christopher A.; Pauls, Thomas; DuvertI, Gilles; Garcia, Paulo; Kuchner, Marc

    2004-01-01

    We present a formal comparison of the performance of algorithms used for synthesis imaging with optical/infrared long-baseline interferometers. Six different algorithms are evaluated based on their performance with simulated test data. Each set of test data is formated in the interferometry Data Exchange Standard and is designed to simulate a specific problem relevant to long-baseline imaging. The data are calibrated power spectra and bispectra measured with a ctitious array, intended to be typical of existing imaging interferometers. The strengths and limitations of each algorithm are discussed.

  13. Aperture masking interferometry research simulation

    NASA Astrophysics Data System (ADS)

    Wang, Haitao; Luo, Qiufeng; Fan, Weijun; Zhang, Xian Ling; Tao, Chunkan; Zhu, Yongtian; Zhou, Bifang; Chen, Hanliang

    2004-10-01

    Aperture Masking Interferometry (AMI) is one of the high-resolution astronomical image observation technologies. It is also an important research way to the Optical Aperture Synthesis (OAS). The theory of OAS is simply introduced and AMI simulation method is raised. The mathematics model is built and the interferogram fringes are got. The aperture mask u-v coverage is discussed and one image reconstruction method is done. The reconstructed image result is got with CLEAN method. Shortcoming of this work is also referred and the future research work is mentioned at last.

  14. Golographic interferometry of physical processes

    NASA Astrophysics Data System (ADS)

    Ostrovskaya, G. V.

    2016-06-01

    This paper is devoted to the contribution of Yuri Ostrovsky to holographic interferometry, one of the fundamental scientific and practical applications of holography. The title of this paper is the same as the title of his doctoral thesis that he defended in 1974, and, as it seems to me, reflects most of the specific features of the majority of his scientific publications, viz., an inseparable link of the methods developed by him with the results obtained with the help of these methods in a wide range of investigations of physical processes and phenomena.

  15. 50 years of holographic interferometry

    NASA Astrophysics Data System (ADS)

    Stetson, Karl A.

    2015-01-01

    Fifty years ago, Robert L. Powell and I discovered holographic interferometry while working at the Radar Laboratory of the University of Michigan's Institute of Science and Technology. I have worked in this field for this entire time span, watched it grow from an unexplored technology to become a widespread industrial testing method, and I have contributed to these developments. In this paper, I will trace my history in this field from our discovery to my involvement in its theory and applications. I will conclude with a discussion of digital holography, which is currently replacing photographic holography for most research and industrial applications.

  16. Photofragmentation Beam Splitters for Matter-Wave Interferometry

    NASA Astrophysics Data System (ADS)

    Dörre, Nadine; Rodewald, Jonas; Geyer, Philipp; von Issendorff, Bernd; Haslinger, Philipp; Arndt, Markus

    2014-12-01

    Extending the range of quantum interferometry to a wider class of composite nanoparticles requires new tools to diffract matter waves. Recently, pulsed photoionization light gratings have demonstrated their suitability for high mass matter-wave physics. Here, we extend quantum interference experiments to a new class of particles by introducing photofragmentation beam splitters into time-domain matter-wave interferometry. We present data that demonstrate this coherent beam splitting mechanism with clusters of hexafluorobenzene and we show single-photon depletion gratings based both on fragmentation and ionization for clusters of vanillin. We propose that photofragmentation gratings can act on a large set of van der Waals clusters and biomolecules which are thermally unstable and often resilient to single-photon ionization.

  17. Phase and fringe order determination in wavelength scanning interferometry.

    PubMed

    Moschetti, Giuseppe; Forbes, Alistair; Leach, Richard K; Jiang, Xiang; O'Connor, Daniel

    2016-04-18

    A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventional fringe frequency-derived z height directly, the method uses the frequency to resolve the fringe order ambiguity, and combine this information with the more accurate and repeatable fringe phase derived z height. A theoretical model to evaluate the method's performance in the presence of additive noise is derived and shown to be in good agreement with experiments. The measurement repeatability is improved by a factor of ten over that achieved when using frequency information alone, reaching the sub-nanometre range. Moreover, the z-axis non-linearity (bleed-through or ripple error) is reduced by a factor of ten. These order of magnitude improvements in measurement performance are demonstrated through a number of practical measurement examples.

  18. Homodyne digital interferometry for a sensitive fiber frequency reference.

    PubMed

    Ngo, Silvie; McRae, Terry G; Gray, Malcolm B; Shaddock, Daniel A

    2014-07-28

    Digitally enhanced homodyne interferometry enables robust interferometric sensitivity to be achieved in an optically simple configuration by shifting optical complexity into the digital signal processing regime. We use digitally enhanced homodyne interferometry in a simple, all-fiber Michelson interferometer to achieve a frequency reference stability of better than 20 Hz/√Hz from 10 mHz to 1 Hz, satisfying, for the first time in an all fiber system, the stability requirements for the Gravity Recovery and Climate Experiment Follow On mission. In addition, we have demonstrated stability that satisfies the future mission objectives at frequencies down to 1 mHz. This frequency domain stability translates into a fractional Allan deviation of 3.3 × 10(-17) for an integration time of 55 seconds.

  19. Intensity control of individual DBD plasma filament. I. Experiment with a needle electrode

    NASA Astrophysics Data System (ADS)

    Paliwoda, M. C.; Rovey, J. L.

    2017-05-01

    Filamentary volume dielectric barrier discharge (DBD) produces patterned plasma structures that are currently being explored for reconfigurable metamaterial applications. In this work, the presence and intensity of a single filament (within an array of filaments) are controlled by biasing a low voltage needle electrode by less than 7% of the driving voltage. The current, voltage, and time-averaged normalized light intensity were measured while varying the needle voltage through self-biasing resistors. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from 80% to 0% of the light intensity of surrounding filaments. When the biased voltage prevents a filament from forming, the voltage difference across the air gap and between the electrodes remains well above the breakdown voltage. Redistributed charge inside the DBD rather than the cross-gap voltage difference is the mechanism which controls the filament intensity when surrounding filaments are present. This work presents a method for controlling an array of plasma filaments with needle electrodes, at voltage biases more manageable for a control circuit.

  20. Testing nonlinear vacuum electrodynamics with Michelson interferometry

    NASA Astrophysics Data System (ADS)

    Schellstede, Gerold O.; Perlick, Volker; Lämmerzahl, Claus

    2015-07-01

    We discuss the theoretical foundations for testing nonlinear vacuum electrodynamics with Michelson interferometry. Apart from some nondegeneracy conditions to be imposed, our discussion applies to all nonlinear electrodynamical theories of the Plebański class, i.e., to all Lagrangians that depend only on the two Lorentz-invariant scalars quadratic in the field strength. The main idea of the experiment proposed here is to use the fact that, according to nonlinear electrodynamics, the phase velocity of light should depend on the strength and on the direction of an electromagnetic background field. There are two possible experimental setups for testing this prediction with Michelson interferometry. The first possibility is to apply a strong electromagnetic field to the beam in one arm of the interferometer and to compare the situation where the field is switched on with the situation where it is switched off. The second possibility is to place the whole interferometer in a strong electromagnetic field and to rotate it. If an electromagnetic field is placed in one arm, the interferometer could have the size of a gravitational wave detector, i.e., an arm length of several hundred meters. If the whole interferometer is placed in an electromagnetic field, one would have to do the experiment with a tabletop interferometer. As an alternative to a traditional Michelson interferometer, one could use a pair of optical resonators that are not bigger than a few centimeters. Then the whole apparatus would be placed in the background field and one would either compare the situation where the field is switched on with the situation where it is switched off or one would rotate the apparatus with the field kept switched on. We derive the theoretical foundations for these types of experiments, in the context of an unspecified nonlinear electrodynamics of the Plebański class, and we discuss their feasibility. A null result of the experiment would place bounds on the parameters of the

  1. Heterodyne Interferometry in InfraRed at OCA-Calern Observatory in the seventies

    NASA Astrophysics Data System (ADS)

    Gay, J.; Rabbia, Y.

    2014-04-01

    We report on various works carried four decades ago, so as to develop Heterodyne Interferometry in InfraRed (10 μm) at Calern Observatory (OCA, France), by building an experiment, whose the acronym "SOIRDETE" means "Synthese d'Ouverture en InfraRouge par Detection hETErodyne". Scientific and technical contexts by this time are recalled, as well as basic principles of heterodyne interferometry. The preliminary works and the SOIRDETE experiment are briefly described. Short comments are given in conclusion regarding the difficulties which have prevented the full success of the SOIRDETE experiment.

  2. Characterization of micro structure through hybrid interference and phase determination in broadband light interferometry.

    PubMed

    Zhou, Yi; Tang, Yan; Zhu, Jiangping; Deng, Qinyuan; Yang, Yong; Zhao, Lixin; Hu, Song

    2017-03-10

    Broadband light interferometry, which is a well-developed method for surface profiling, has been applied with great success in the past years. Conventional multi-wavelength interferometric surface profilers mostly utilize the light irradiance to locate the zero fringe order, but the accuracy and stability can be negatively influenced by intensity fluctuations and external light disturbance, which is a serious problem. In this paper we discuss a hybrid technique combining light intensity and spectral modulation to determine zero optical path difference in which the light instability can be effectively suppressed. Additionally, the phase evaluation at each pixel will provide a high vertical resolution to obtain the characterization of the micro structure. The hybrid-interference method will not only improve the sensitivity of the measurement system but also level up the robustness and stability. Both simulation and experiment on a micro-dome structure have been presented to verify the effectiveness. Furthermore, the proposed method may be promising to replace the previously intensity-based method, especially in a complex application environment.

  3. Multi-Photon Quantum Interferometry

    NASA Astrophysics Data System (ADS)

    Bouwmeester, Dirk

    2007-06-01

    Based on the investigation of multi-photon entanglement, as produced by stimulated parametric down-conversion, a technique is presented to create heralded ``noon'' states. The relevance for interferometry will be discussed. Furthermore we explored the use of photon-number resolving detectors in Mach-Zehnder type of interferometers. Our current detectors can distinguish 0, 1, 2, to7, photon impacts. Although the overall collection and detection efficiency of photons is well below unity (about 0.3) the photon number resolving property is still very useful if combined with coherent input states since those state are eigenstates of the photon annihilation operator. First we analyze the coherent state interferometer with a single photon-number resolving detector, revealing the strong non-linear response of an interferometer in the case of Fock-state projection. Second, we use two such detectors together with a Baysian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift. This protocol is unbiased and saturates the Cramer-Rao phase uncertainty bound and, therefore, is an optimal phase estimation strategy. As a final topic it will be shown how quantum interferometry combined with micromechanical structures can be used to investigate quantum superpositions and quantum decoherence of macroscopic objects.

  4. Family members' experiences of being cared for by nurses and physicians in Norwegian intensive care units: a phenomenological hermeneutical study.

    PubMed

    Frivold, Gro; Dale, Bjørg; Slettebø, Åshild

    2015-08-01

    When patients are admitted to intensive care units, families are affected. This study aimed to illuminate the meaning of being taken care of by nurses and physicians for relatives in Norwegian intensive care units. Thirteen relatives of critically ill patients treated in intensive care units in southern Norway were interviewed in autumn 2013. Interview data were analysed using a phenomenological hermeneutical method inspired by the philosopher Paul Ricoeur. Two main themes emerged: being in a receiving role and being in a participating role. The receiving role implies experiences of informational and supportive care from nurses and physicians. The participating role implies relatives' experiences of feeling included and being able to participate in caring activities and decision-making processes. The meaning of being a relative in ICU is experienced as being in a receiving role, and at the same time as being in a participating role. Quality in relations is described as crucial when relatives share their experiences of care by nurses and physicians in the ICU. Those who experienced informational and supportive care, and who had the ability to participate, expressed feelings of gratitude and confidence in the healthcare system. In contrast, those who did not experience such care, especially in terms of informational care expressed feelings of frustration, confusion and loss of confidence. However, patient treatment and care outweighed relatives' own feelings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Optical-fiber vibration sensor using step interferometry.

    PubMed

    Ferrari, J A; García, P

    1996-10-01

    An all-fiber vibration sensor based on step interferometry is described. The sensor consists of a modified Michelson interferometer in which the ends of the reference and signal arms are assembled and fixed together to produce regular distributed interference fringes. Five photodetectors with relative phase shifts of π/2 placed on the fringes acquire five intensity patterns simultaneously. One reconstructs the vibration amplitude by using the well-known five-step algorithm. A vibration sensor with these characteristics was constructed, and its performance was investigated.

  6. High intensity surge and seasonal effects in the dark current of the Nimbus-4 BUV experiment

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Goldberg, R. A.; Vette, J. I.; Felton, L. L.

    1981-01-01

    Seasonal global maps of the dark current produced by corpuscular radiation contributing to the background level of the Nimbus-4 Backscattered Ultraviolet (BUV) instrument were developed, using BUV monochrometer nighttime data in the pulse counting mode during solar and magnetically quiet periods. The existence of high intensity surges has been discovered which occur on a sporadic basis and which cause sufficient enhancements of dark current within the subauroral regions to produce background levels similar to those within the South Atlantic anomaly. Examples are provided of the nominal quiet dark current intensity maps, and the variability and implications of the surge data are discussed.

  7. Multifrequency perturbations in matter-wave interferometry

    NASA Astrophysics Data System (ADS)

    Günther, A.; Rembold, A.; Schütz, G.; Stibor, A.

    2015-11-01

    High-contrast matter-wave interferometry is essential in various fundamental quantum mechanical experiments as well as for technical applications. Thereby, contrast and sensitivity are typically reduced by decoherence and dephasing effects. While decoherence accounts for a general loss of quantum information in a system due to entanglement with the environment, dephasing is due to collective time-dependent external phase shifts, which can be related to temperature drifts, mechanical vibrations, and electromagnetic oscillations. In contrast to decoherence, dephasing can, in principle, be reversed. Here, we demonstrate in experiment and theory a method for the analysis and reduction of the influence of dephasing noise and perturbations consisting of several external frequencies in an electron interferometer. This technique uses the high spatial and temporal resolution of a delay-line detector to reveal and remove dephasing perturbations by second-order correlation analysis. It allows matter-wave experiments under perturbing laboratory conditions and can be applied, in principle, to electron, atom, ion, neutron, and molecule interferometers.

  8. Bibliography of spatial interferometry in optical astronomy

    NASA Technical Reports Server (NTRS)

    Gezari, Daniel Y.; Roddier, Francois; Roddier, Claude

    1990-01-01

    The Bibliography of Spatial Interferometry in Optical Astronomy is a guide to the published literature in applications of spatial interferometry techniques to astronomical observations, theory and instrumentation at visible and infrared wavelengths. The key words spatial and optical define the scope of this discipline, distinguishing it from spatial interferometry at radio wavelengths, interferometry in the frequency domain applied to spectroscopy, or more general electro-optics theoretical and laboratory research. The main bibliography is a listing of all technical articles published in the international scientific literature and presented at the major international meetings and workshops attended by the spatial interferometry community. Section B summarizes publications dealing with the basic theoretical concepts and algorithms proposed and applied to optical spatial interferometry and imaging through a turbulent atmosphere. The section on experimental techniques is divided into twelve categories, representing the most clearly identified major areas of experimental research work. Section D, Observations, identifies publications dealing specifically with observations of astronomical sources, in which optical spatial interferometry techniques have been applied.

  9. An Intensive Programme on Education for Sustainable Development: The Participants' Experience

    ERIC Educational Resources Information Center

    Biasutti, Michele

    2015-01-01

    This paper presents the framework of an intensive programme (IP) organised by UNESCO and addressed to young graduate professionals to prepare them for a career in fields related to sustainability. The aims of the IP were to address participants' environmental awareness and to develop attitudes and skills related to environmental planning and…

  10. Effects of an Intensive Disability-Focused Training Experience on University Faculty Self-Efficacy

    ERIC Educational Resources Information Center

    Murray, Christopher; Lombardi, Allison; Seely, John R.; Gerdes, Hilary

    2014-01-01

    The current study evaluates the short-term effects of a disability-focused training on the disability-related self-efficacy of university faculty. Three consecutive cohorts of faculty (N = 102) participated in an intensive four-day training institute focused on understanding and supporting university students with disabilities. Self-efficacy for…

  11. Housestaff Experience, Workload, and Test Ordering in a Neonatal Intensive Care Unit.

    ERIC Educational Resources Information Center

    Griffith, Charles H., III; And Others

    1996-01-01

    A study of the workload of nine medical interns and seven residents in a neonatal intensive care nursery investigated the number of X-rays, arterial blood gas analyses (ABGs), and electrolyte determinations ordered for 321 infants over 5 months. Results show that as the workload increased, interns ordered ABGs more often than residents, especially…

  12. Reverse Transfer: Experiences of International Chinese Students in Intensive English Programs

    ERIC Educational Resources Information Center

    Zhang, Yi

    2015-01-01

    An increasing number of international Chinese undergraduate students enrolled in United States.colleges and universities in the past few years. Many began their journey in an intensive English program of a four-year university due to lack of English proficiency. Instead of continuing their study at the same institution, a considerable number of…

  13. Saying It "More Intensely": Using Sensory Experience To Teach Poetry Writing.

    ERIC Educational Resources Information Center

    Baart, Nicole

    2002-01-01

    Suggests the best way to help high school students write poetry is to bring them to memories that would stimulate the expression of everything more intensely. Describes four workshops that appeal to the senses: scent writing, taste writing, music writing, and sight writing. (RS)

  14. Carbon Sequestration and intensive silviculture: The southern U.S. Experience

    NASA Astrophysics Data System (ADS)

    Jose, S.

    2006-05-01

    Carbon sequestration by managed forests in the U.S. accounts for nearly 300 MMTC per year, which is eighteen times more than the C sequestered by croplands and 36 times more than that sequestered by rangelands. The Western forests used to produce majority of the forest biomass (as timber and fiber) in the U.S. However, changing social values and attitudes are shifting harvesting pressure from the western forests to the southeastern forests. As a result of these and other factors, the South's forest biomass production more than doubled between 1953 and 1997. Its share of U.S. production rose from 41 to 58 percent and its share of the world's production from 6.3 to 15.8 percent. This represents a significant gain in the carbon sequestration potential of managed forests in the South. It is estimated that the managed forests of the South sequester nearly 100 MMTC per year or accounts for third of the carbon storage capacity of the continental U.S. forests. The remarkable gain in carbon sequestration potential of the southern forests, despite a shrinking forestland base, was made possible by intensive silviculture. How did intensive silviculture help sequester more carbon? This paper examines the ecological and physiological basis for the observed increases in productivity and carbon sequestration potential of intensively managed forests of the South. It also explores ways by which carbon sequestration can be further enhanced in intensive forestry.

  15. Collaborative Teaching in an Intensive Spanish Course: A Professional Development Experience for Teaching Assistants

    ERIC Educational Resources Information Center

    Stepp-Greany, Jonita

    2004-01-01

    This pilot project was designed to provide professional development to teaching assistants (TAs) and improve undergraduate instruction in an intensive Spanish course through the use of collaboration and experiential instruction. TAs improved their teaching strategies, learned techniques to solve classroom problems, and reported satisfaction from…

  16. An Intensive Programme on Education for Sustainable Development: The Participants' Experience

    ERIC Educational Resources Information Center

    Biasutti, Michele

    2015-01-01

    This paper presents the framework of an intensive programme (IP) organised by UNESCO and addressed to young graduate professionals to prepare them for a career in fields related to sustainability. The aims of the IP were to address participants' environmental awareness and to develop attitudes and skills related to environmental planning and…

  17. Experience from multidisciplinary follow-up on critically ill patients treated in an intensive care unit.

    PubMed

    Fonsmark, Lise; Rosendahl-Nielsen, Mette

    2015-05-01

    International literature describes that former intensive care unit (ICU) patients suffer considerable physical and neuropsychological complications. Systematic data on Danish ICU survivors are scarce as standardised follow-up after intensive care has yet to be described. This article describes and evaluates the knowledge gained from outpatient follow-up at a tertiary intensive care unit at Rigshospitalet, Copenhagen, during a three-year period. A total of 101 adult former ICU patients attended the outpatient clinic over a three-year period. Patients included were medical and surgical patients with a length of stay exceeding four days. Patients attended the clinic after discharge from hospital and for a minimum of two months from their discharge from the ICU. The patients were assessed for physical, neuropsychological and psychological problems and, if necessary, further treatment or rehabilitation was initiated. Reduced physical ability was seen in 82%. A total of 89% suffered a substantial weight loss. 83.2% had signs indicating acute brain dysfunction during the ICU stay, and approximately half of the patients still had cognitive problems. A total of 66 interventions were initiated. Our data confirmed that a large proportion of ICU survivors suffer considerable long-term physical and neuropsychological sequelae. Intensive care follow-up may contribute to address these specific problems and to initiate the needed interventions. Research is needed to determine whether specialised rehabilitation is required. not relevant. not relevant.

  18. Creating a Transformational Learning Experience: Immersing Students in an Intensive Interdisciplinary Learning Environment

    ERIC Educational Resources Information Center

    White, Shelley K.; Nitkin, Mindell Reiss

    2014-01-01

    The Simmons World Challenge is a unique, interdisciplinary program recently developed at Simmons College. It immerses students in an intensive winter-session course that challenges them to tackle a pressing social issue, such as poverty or hunger, and create actionable solutions to the problem. The program was conceived and designed to harness the…

  19. Strengthening Collaborative Capacity: Experiences from a Short, Intensive Field Course on Ecosystems, Health and Society

    ERIC Educational Resources Information Center

    Parkes, Margot W.; Saint-Charles, Johanne; Cole, Donald C.; Gislason, Maya; Hicks, Elisabeth; Le Bourdais, Courtney; McKellar, Kaileah A.; St-Cyr Bouchard, Maude

    2017-01-01

    A key capacity for engagement in the emerging field of ecohealth is the ability to work collaboratively. Between 2008 and 2010, the Canadian Community of Practice in Ecosystem Approaches to Health collectively designed and delivered three foundational, intensive, field courses. This paper presents findings derived from both quantitative and…

  20. Families' experiences of their interactions with staff in an Australian intensive care unit (ICU): a qualitative study.

    PubMed

    Wong, Pauline; Liamputtong, Pranee; Koch, Susan; Rawson, Helen

    2015-02-01

    Nursing is characterised as a profession that provides holistic, person-centred care. Due to the condition of the critically ill, a family-centred care model is more applicable in this context. Furthermore, families are at risk of emotional and psychological distress, as a result of the admission of their relative to intensive care. The families' experiences of their interactions in intensive care have the potential to enhance or minimise this risk. This paper presents a subset of findings from a broader study exploring families of critically ill patients' experiences of their interactions with staff, their environment, the patient and other families, when their relative is admitted to an Australian intensive care unit. By developing an understanding of their experience, nurses are able to implement interventions to minimise the families' distress, while providing more holistic, person- and family-centred care. The study was a qualitative enquiry that adopted the grounded theory approach for data collection and analysis. In-depth interviews with family members occurred between 2009 and 2011, allowing the thoughts on interactions experienced by those families, to be explored. Data were analysed thematically. Twelve family members of 11 patients participated in this study. This study was undertaken in a mixed intensive care unit of a large metropolitan hospital in Australia. Interactions experienced by families of the critically ill primarily revolved around seeking information and becoming informed. Further examination of the interviews suggested that staff interacted in supportive ways due to their communication and interpersonal skills. However, families also experienced unsupportive interactions as a result of poor communication. Facilitating communication and interacting in supportive ways should help alleviate the anxiety and distress experienced by families of the critically ill in the intensive care unit. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Atom interferometry in an optical cavity

    NASA Astrophysics Data System (ADS)

    Hamilton, Paul; Jaffe, Matt; Brown, Justin; Maisenbacher, Lothar; Estey, Brian; Müller, Holger

    2014-05-01

    We have demonstrated the first light pulse atom interferometer using an in-vacuum optical cavity to generate the matter wave beamsplitters. An optical cavity allows for a compact setup with several advantages over traditional atom interferometers. Even with modest laser power, large intracavity intensity should enable high order multiphoton beamsplitters which increase the sensitivity of an interferometer. Clean wavefronts from spatial mode filtering can reduce contrast loss for both light pulse interferometers as well as optical lattice based interferometers. In addition, well-defined spatial modes allow many useful properties such as the beam size, waist position, and divergence to be determined with high accuracy. Finally, the use of high order transverse spatial modes gives multiple self-aligned beams useful in applications such as Sagnac interferometry for rotation sensing. We discuss our recent investigations into novel beamsplitters and interferometer geometries in the optical cavity and the implications for a compact inertial sensor as well as measurements of the gravitational Aharanov-Bohm effect and Newton's gravitational constant.

  2. Laser Wakefield diagnostic using holographic longitudinal interferometry

    SciTech Connect

    Volfbeyn, P.; Esarey, E.; Leemans, W.P.

    1999-03-26

    We propose a diagnostic technique for wakefield measurement in plasma channels. A new technique for plasma channel creation, the Ignitor Heater scheme was proposed and experimentally tested in hydrogen and nitrogen previously. It makes use of two laser pulses. The Ignitor, an ultrashort (sub 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used to heat the existing spark via in-verse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. Laser pulses injected into such plasma channels produce a plasma wake that has a phase velocity close to the speed of light. A discussion of plasma wake measurements, using a Longitudinal Interferometry Wakefield Diagnostic Based on Time Domain Rayleigh Refractometry with Holographic Inversion, will be presented.

  3. Dependence of the muon intensity on the atmospheric temperature measured by the GRAPES-3 experiment

    NASA Astrophysics Data System (ADS)

    Arunbabu, K. P.; Ahmad, S.; Chandra, A.; Dugad, S. R.; Gupta, S. K.; Hariharan, B.; Hayashi, Y.; Jagadeesan, P.; Jain, A.; Jhansi, V. B.; Kawakami, S.; Kojima, H.; Mohanty, P. K.; Morris, S. D.; Nayak, P. K.; Oshima, A.; Rao, B. S.; Reddy, L. V.; Shibata, S.; Tanaka, K.; Zuberi, M.

    2017-09-01

    The large area (560 m2) GRAPES-3 tracking muon telescope has been operating uninterruptedly at Ooty, India since 2001. Every day, it records 4 × 109 muons of ≥1 GeV with an angular resolution of ∼4°. The variation of atmospheric temperature affects the rate of decay of muons produced by the galactic cosmic rays (GCRs), which in turn modulates the muon intensity. By analyzing the GRAPES-3 data of six years (2005-2010), a small (amplitude ∼0.2%) seasonal variation (1 year (Yr) period) in the intensity of muons could be measured. The effective temperature 'Teff' of the upper atmosphere also displays a periodic variation with an amplitude of ∼1 K which was responsible for the observed seasonal variation in the muon intensity. At GeV energies, the muons detected by the GRAPES-3 are expected to be anti-correlated with Teff. The anti-correlation between the seasonal variation of Teff, and the muon intensity was used to measure the temperature coefficient αT by fast Fourier transform (FFT) technique. The magnitude of αT was found to scale with the assumed attenuation length 'λ' of the hadrons in the range λ = 80-180 g cm-2. However, the magnitude of the correction in the muon intensity was found to be almost independent of the value of λ used. For λ = 120 g cm-2 the value of temperature coefficient αT was found to be (- 0.17 ± 0.02)% K-1.

  4. Acute Respiratory Failure in Renal Transplant Recipients: A Single Intensive Care Unit Experience.

    PubMed

    Ulas, Aydin; Kaplan, Serife; Zeyneloglu, Pinar; Torgay, Adnan; Pirat, Arash; Haberal, Mehmet

    2015-11-01

    Frequency of pulmonary complications after renal transplant has been reported to range from 3% to 17%. The objective of this study was to evaluate renal transplant recipients admitted to an intensive care unit to identify incidence and cause of acute respiratory failure in the postoperative period and compare clinical features and outcomes between those with and without acute respiratory failure. We retrospectively screened the data of 540 consecutive adult renal transplant recipients who received their grafts at a single transplant center and included those patients admitted to an intensive care unit during this period for this study. Acute respiratory failure was defined as severe dyspnea, respiratory distress, decreased oxygen saturation, hypoxemia or hypercapnia on room air, or requirement of noninvasive or invasive mechanical ventilation. Among the 540 adult renal transplant recipients, 55 (10.7%) were admitted to an intensive care unit, including 26 (47.3%) admitted for acute respiratory failure. Median time from transplant to intensive care unit admission was 10 months (range, 0-67 mo). The leading causes of acute respiratory failure were bacterial pneumonia (56%) and cardiogenic pulmonary edema (44%). Mean partial pressure of arterial oxygen to fractional inspired oxygen ratio was 174 ± 59, invasive mechanical ventilation was used in 13 patients (50%), and noninvasive mechanical ventilation was used in 8 patients (31%). The overall mortality was 16.4%. Acute respiratory failure was the reason for intensive care unit admission in almost half of our renal transplant recipients. Main causes of acute respiratory failure were bacterial pneumonia and cardiogenic pulmonary edema. Mortality of patients admitted for acute respiratory failure was similar to those without acute respiratory failure.

  5. Applications of chirped Raman adiabatic rapid passage to atom interferometry

    NASA Astrophysics Data System (ADS)

    Kotru, Krish; Butts, David L.; Kinast, Joseph M.; Johnson, David M. S.; Radojevic, Antonije M.; Timmons, Brian P.; Stoner, Richard E.

    2012-02-01

    We present robust atom optics, based on chirped Raman adiabatic rapid passage (ARP), in the context of atom interferometry. Such ARP light pulses drive coherent population transfer between two hyperfine ground states by sweeping the frequency difference of two fixed-intensity optical fields with large single photon detunings. Since adiabatic transfer is less sensitive to atom temperature and non-uniform Raman beam intensity than standard Raman pulses, this approach should improve the stability of atom interferometers operating in dynamic environments. In such applications, chirped Raman ARP may also provide advantages over the previously demonstrated stimulated Raman adiabatic passage (STIRAP) technique, which requires precise modulation of beam intensity and zeroing of the single photon detuning. We demonstrate a clock interferometer with chirped Raman ARP pulses, and compare its stability to that of a conventional Raman pulse interferometer. We also discuss potential improvements to inertially sensitive atom interferometers. Copyright 2011 by The Charles Stark Draper Laboratory, Inc. All rights reserved.

  6. High sensitivity moiré interferometry with compact achromatic interferometry

    NASA Astrophysics Data System (ADS)

    Czarnek, Robert

    Experimental observations and measurements are the sources of information essential for correct development of mathematical models of real structural materials. Moiré interferometry offers high sensitivity in full-field measurements of in-plane displacements on the surface of a specimen. Although it is a powerful method in experimental stress analysis, it has some shortcomings. One is that existing systems require highly coherent light. The only sufficient source of light for this application is a long cavity laser, which is relatively expensive and at best cumbersome. Another shortcoming is that measurements must be performed in a vibration-free environment, such as that found on a holographic table. These requirements limit the use of existing moiré interferometers to a holographic laboratory. In this paper a modified concept of compensation is presented, which permits the use of a chromatic source of light in a compact moiré system. The compensator provides order in the angles of incident light for each separate wavelength, so that the virtual reference grating created by each wavelength in a continuous spectrum is identical in frequency and spatial position. The result is a virtual reference grating that behaves exactly like that created in coherent light. With this development the use of a laser diode, which is a non-coherent light source of tiny dimensions, becomes practical. The special configuration of the optics that create the virtual grating allows its synchronization with the specimen grating and leads to an interferometer design that is relatively insensitive to the vibrations found in a mechanical testing laboratory. Sensitivity to relative motion is analyzed theoretically. This development provides the oppurtunity to apply moiré interferometry to solid mechanics problems that cannot be studied in an optics laboratory. Experimental verification of the optical concepts is provided. A compact moiré interferometer based on the presented idea was

  7. Full-sensitivity depth-resolved measurements of displacement fields inside weakly scattering materials using wavelength scanning interferometry

    NASA Astrophysics Data System (ADS)

    Ruiz, Pablo D.; Chakraborty, Semanti

    2012-10-01

    This paper extends Digital Speckle Pattern Interferometry into three dimensions. A Wavelength Scanning Interferometry (WSI) system is proposed which provides displacement fields inside the volume of semi-transparent scattering materials with high spatial resolution and three-dimensional displacement sensitivity. The main driver to develop such a system is the need to determine constitutive parameters (mainly elastic constants) of materials such as polymers and biological tissues so that their behavior can be modeled computationally. The sample is illuminated by three non-coplanar collimated beams around the observation direction. Sequences of two-dimensional interferograms are recorded while the frequency of the laser is tuned at a constant rate. Each pixel thus records and intensity signal which temporal frequency encodes the optical path difference between the illumination and reference beams for a particular point on the sample. Fourier transformation along the time axis reconstructs the magnitude and phase of the material's microstructure. Different optical paths along each illumination direction are required in order to separate or multiplex, in the frequency domain, the signals corresponding to each sensitivity vector. In this way, all the information required to reconstruct the location and the 3D displacement vector of scattering points within the volume in the material is recorded simultaneously. A controlled validation experiment is performed, which confirms the ability of the technique to provide three dimensional displacement distributions inside semitransparent scattering materials.

  8. Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends

    ERIC Educational Resources Information Center

    Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

    2011-01-01

    X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

  9. Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends

    ERIC Educational Resources Information Center

    Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

    2011-01-01

    X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

  10. Optical Long Baseline Interferometry News (OLBIN)

    NASA Astrophysics Data System (ADS)

    Lawson, Peter R.; Malbet, Fabien

    2010-07-01

    The Optical Long Baseline Interferometry News (OLBIN) is a website and forum for scientists, engineers, and students who share a common interest in long-baseline stellar interferometry. Through OLBIN you will find links to projects devoted to stellar interferometry, as well as news items, recent papers and preprints, notices of upcoming meetings, and resources for further research. This paper describes the history of the website, how it has evolved to serve the community, and the current plans for its future development. The website can be found at http://olbin.jpl.nasa.gov/.

  11. Harnessing spectral property of dual wavelength white LED to improve vertical scanning interferometry.

    PubMed

    Chong, Wee Keat; Li, Xiang; Soh, Yeng Chai

    2013-07-01

    Unlike a conventional white light source that emits a continuous and broad spectrum of light, the dual wavelength white light emitting diode (LED) generates white light by mixing blue and yellow lights, so there are two distinct peaks in its intensity spectrum. Prior works had shown that the spectral property of the dual wavelength white LED can affect the vertical scanning interferometry negatively if the spectral effects are not compensated. In this paper, we shall examine this issue by modeling the spectral property and variation of the dual wavelength white LED, followed by investigating its effects on the interference signal of vertical scanning interferometry. Instead of compensating the spectral effects of the dual wavelength white LED, we harness its spectral property to improve the performance of a phase-based height reconstruction algorithm in vertical scanning interferometry.

  12. Experiment and simulation of novel liquid crystal plasma mirrors for high contrast, intense laser pulses

    PubMed Central

    Poole, P. L.; Krygier, A.; Cochran, G. E.; Foster, P. S.; Scott, G. G.; Wilson, L. A.; Bailey, J.; Bourgeois, N.; Hernandez-Gomez, C.; Neely, D.; Rajeev, P. P.; Freeman, R. R.; Schumacher, D. W.

    2016-01-01

    We describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in-situ. We also present novel particle-in-cell simulations that for the first time incorporate multiphoton ionization and dielectric models that are necessary for describing plasma mirrors. Dielectric plasma mirrors are a crucial component for high intensity laser applications such as ion acceleration and solid target high harmonic generation because they greatly improve pulse contrast. We use the liquid crystal 8CB and introduce an innovative dynamic film formation device that can tune the film thickness so that it acts as its own antireflection coating. Films can be formed at a prolonged, high repetition rate without the need for subsequent realignment. High intensity reflectance above 75% and low-field reflectance below 0.2% are demonstrated, as well as initial ion acceleration experimental results that demonstrate increased ion energy and yield on shots cleaned with these plasma mirrors. PMID:27557592

  13. Experiment and simulation of novel liquid crystal plasma mirrors for high contrast, intense laser pulses

    SciTech Connect

    Poole, P. L.; Krygier, A.; Cochran, G. E.; Foster, P. S.; Scott, G. G.; Wilson, L. A.; Bailey, J.; Bourgeois, N.; Hernandez-Gomez, C.; Neely, D.; Rajeev, P. P.; Freeman, R. R.; Schumacher, D. W.

    2016-08-25

    Here, we describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in-situ. We also present novel particle-in-cell simulations that for the first time incorporate multiphoton ionization and dielectric models that are necessary for describing plasma mirrors. Dielectric plasma mirrors are a crucial component for high intensity laser applications such as ion acceleration and solid target high harmonic generation because they greatly improve pulse contrast. We use the liquid crystal 8CB and introduce an innovative dynamic film formation device that can tune the film thickness so that it acts as its own antireflection coating. Films can be formed at a prolonged, high repetition rate without the need for subsequent realignment. High intensity reflectance above 75% and low-field reflectance below 0.2% are demonstrated, as well as initial ion acceleration experimental results that demonstrate increased ion energy and yield on shots cleaned with these plasma mirrors.

  14. Experiment and simulation of novel liquid crystal plasma mirrors for high contrast, intense laser pulses.

    PubMed

    Poole, P L; Krygier, A; Cochran, G E; Foster, P S; Scott, G G; Wilson, L A; Bailey, J; Bourgeois, N; Hernandez-Gomez, C; Neely, D; Rajeev, P P; Freeman, R R; Schumacher, D W

    2016-08-25

    We describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in-situ. We also present novel particle-in-cell simulations that for the first time incorporate multiphoton ionization and dielectric models that are necessary for describing plasma mirrors. Dielectric plasma mirrors are a crucial component for high intensity laser applications such as ion acceleration and solid target high harmonic generation because they greatly improve pulse contrast. We use the liquid crystal 8CB and introduce an innovative dynamic film formation device that can tune the film thickness so that it acts as its own antireflection coating. Films can be formed at a prolonged, high repetition rate without the need for subsequent realignment. High intensity reflectance above 75% and low-field reflectance below 0.2% are demonstrated, as well as initial ion acceleration experimental results that demonstrate increased ion energy and yield on shots cleaned with these plasma mirrors.

  15. Safe intravenous administration in pediatrics: A 5-year Pediatric Intensive Care Unit experience with smart pumps.

    PubMed

    Manrique-Rodríguez, S; Sánchez-Galindo, A C; Fernández-Llamazares, C M; Calvo-Calvo, M M; Carrillo-Álvarez, Á; Sanjurjo-Sáez, M

    2016-10-01

    To estimate the impact of smart pump implementation in a pediatric intensive care unit in terms of number and type of administration errors intercepted. Observational, prospective study carried out from January 2010 to March 2015 with syringe and great volumen infusion pumps available in the hospital. A tertiary level hospital pediatric intensive care unit. Infusions delivered with infusion pumps in all pediatric intensive care unit patients. Design of a drug library with safety limits for all intravenous drugs prescribed. Users' compliance with drug library as well as number and type of errors prevented were analyzed. Two hundred and eighty-three errors were intercepted during 62 months of study. A high risk drug was involved in 58% of prevented errors, such as adrenergic agonists and antagonists, sedatives, analgesics, neuromuscular blockers, opioids, potassium and insulin. Users' average compliance with the safety software was 84%. Smart pumps implementation has proven effective in intercepting high risk drugs programming errors. These results might be exportable to other critical care units, involving pediatric or adult patients. Interdisciplinary colaboration is key to succeed in this process. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  16. Academics' Perceptions of the Purpose of Undergraduate Research Experiences in a Research-Intensive Degree

    ERIC Educational Resources Information Center

    Wilson, Anna; Howitt, Susan; Wilson, Kate; Roberts, Pam

    2012-01-01

    The inclusion of research experiences as core components of undergraduate curricula implies that students will be exposed to and situated within the research activities of their university. Such experiences thus provide a new prism through which to view the relations between teaching, research and learning. The intentions and actions of academics…

  17. Academics' Perceptions of the Purpose of Undergraduate Research Experiences in a Research-Intensive Degree

    ERIC Educational Resources Information Center

    Wilson, Anna; Howitt, Susan; Wilson, Kate; Roberts, Pam

    2012-01-01

    The inclusion of research experiences as core components of undergraduate curricula implies that students will be exposed to and situated within the research activities of their university. Such experiences thus provide a new prism through which to view the relations between teaching, research and learning. The intentions and actions of academics…

  18. Post-Newtonian gravitational effects in optical interferometry

    NASA Astrophysics Data System (ADS)

    Brodutch, Aharon; Gilchrist, Alexei; Guff, Thomas; Smith, Alexander R. H.; Terno, Daniel R.

    2015-03-01

    We investigate general optical interferometry in stationary spacetimes focusing on quantum-optical experiments in near-Earth environments. We provide a rigorous expression for the gravitationally induced phase difference and adapt the parametrized post-Newtonian formalism for calculations of polarization rotation. We investigate two optical versions of the Colella-Overhauser-Werner experiment and show that the phase difference is independent of the post-Newtonian parameter γ , making it a possible candidate for an optical test of the Einstein equivalence principle. Polarization rotation provides an example of the quantum clock variable and, while related to the optical Lense-Thirring effects, shows a qualitatively different behavior from them.

  19. Frequency-modulated light scattering interferometry used for assessment of optical properties in turbid media

    NASA Astrophysics Data System (ADS)

    Mei, Liang; Somesfalean, Gabriel; Svanberg, Sune

    2013-02-01

    Frequency-modulated light scattering interferometry, which employs a frequency-modulated coherent light source and examines the intensity fluctuation of the resulting scattered light using a heterodyne detection scheme, was utilized to evaluate the optical properties of liquid phantoms made of Intralipid® and Indian ink. Based on the diffusion theory, nonlinear fits to the power spectrum of the heterodyne-detected light intensity are performed and discussed in detail, and the optical properties of liquid phantoms are consequently retrieved.

  20. Parents' experiences with neonatal home care following initial care in the neonatal intensive care unit: a phenomenological hermeneutical interview study.

    PubMed

    Dellenmark-Blom, Michaela; Wigert, Helena

    2014-03-01

    A descriptive study of parents' experiences with neonatal home care following initial care in the neonatal intensive care unit. As survival rates improve among premature and critically ill infants with an increased risk of morbidity, parents' responsibilities for neonatal care grow in scope and degree under the banner of family-centred care. Concurrent with medical advances, new questions arise about the role of parents and the experience of being provided neonatal care at home. An interview study with a phenomenological hermeneutic approach. Parents from a Swedish neonatal (n = 22) home care setting were extensively interviewed within one year of discharge. Data were collected during 2011-2012. The main theme of the findings is that parents experience neonatal home care as an inner emotional journey, from having a child to being a parent. This finding derives from three themes: the parents' experience of leaving the hospital milieu in favour of establishing independent parenthood, maturing as a parent and processing experiences during the period of neonatal intensive care. This study suggests that neonatal home care is experienced as a care structure adjusted to incorporate parents' needs following discharge from a neonatal intensive care unit. Neonatal home care appears to bridge the gap between hospital and home, supporting the family's adaptation to life in the home setting. Parents become empowered to be primary caregivers, having nurse consultants serving the needs of the whole family. Neonatal home care may therefore be understood as the implementation of family-centred care during the transition from NICU to home. © 2013 John Wiley & Sons Ltd.

  1. Synthetic aperture interferometry: error analysis

    SciTech Connect

    Biswas, Amiya; Coupland, Jeremy

    2010-07-10

    Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt.42, 701 (2003)].APOPAI0003-693510.1364/AO.42.000701 A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt.47, 1705 (2008)].APOPAI0003-693510.1364/AO.47.001705 Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.

  2. Recording materials for holographic interferometry

    NASA Astrophysics Data System (ADS)

    Grichine, Mikhail V.; Skokov, Gleb R.; Ratcliffe, David B.; Kumonko, Petr I.; Sazonov, Yury A.

    1999-08-01

    We present a general review of our current recording materials suitable for laser interferometry applications. The review will cover fine-grain Silver-Halide materials sensitive to the red (PFG-01) and green (VRP-M) spectral ranges. These products have characteristics very similar to the old Agfa products 8E75 and 8E56. Additionally ultra-fine grain red-sensitive and panchromatic Silver-Halide materials will be covered as well as products based on dichromated gelatin. In each case detailed characteristics of each emulsion type will be presented and recommended processing schemes will be discussed in the context of both Pulsed and CW radiation sources. The choice of commercially available substrate and material dimensions will be mentioned.

  3. Moire interferometry with increased sensitivity

    NASA Astrophysics Data System (ADS)

    Han, Bongtae; Post, Daniel

    The basic sensitivity of moire interferometry was increased beyond the previously conceived theoretical limit. This was accomplished by creating the virtual reference grating inside a refractive medium instead of air, thus shortening the wavelength of light. A very compact four-beam moire interferometer in a refractive medium was developed for microscopic viewing, which produced a basic sensitivity of 208 nm per fringe order, corresponding to moire with 4800 lines per mm. Its configuration made it inherently stable and relatively insensitive to environmental disturbances. An optical microscope was employed as the image recording system to obtain high spatial resolution. The method was demonstrated for deformation of a thick graphite/epoxy composite at the 0/90 deg ply interface.

  4. Study of femtosecond laser spectrally resolved interferometry distance measurement based on excess fraction method

    NASA Astrophysics Data System (ADS)

    Ji, Rongyi; Hu, Kun; Li, Yao; Gao, Shuyuan; Zhou, Weihu

    2017-02-01

    Spectrally resolved interferometry (SRI) technology is a high precision laser interferometry technology, whose short non-ambiguity range (NAR) increases the precision requirement of pre-measurement in absolute distance measurement. In order to improve NAR of femtosecond laser SRI, the factors affecting NAR are studied in measurement system, and synthetic NAR method is presented based on excess fraction method to solve this question. A theoretical analysis is implemented and two Fabry-Perot Etalons with different free spectral range are selected to carry out digital simulation experiments. The experiment shows that NAR can be improved using synthetic NAR method and the precision is the same with that of fundamental femtosecond laser SRI.

  5. The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

    PubMed Central

    Carbone, Ludovico; Fulda, Paul; Bond, Charlotte; Brueckner, Frank; Brown, Daniel; Wang, Mengyao; Lodhia, Deepali; Palmer, Rebecca; Freise, Andreas

    2013-01-01

    Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light. We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry. PMID:23962813

  6. An intense and unforgettable experience: the lived experience of malignant wounds from the perspectives of patients, caregivers and nurses.

    PubMed

    Alexander, Susan J

    2010-12-01

    Malignant wounds occur infrequently, but are typically described as devastating and overwhelming. However, there has been little formalised research, and the vast majority of existing malignant wound literature comprises reports of health care professionals from their management of the physical symptoms. Few studies have investigated the lived experience from the perspectives of patients and nurses and none have investigated the experiences of lay caregivers caring for a patient with a malignant wound. As a result, there has been little mention in existing literature of the non physical issues associated with malignant wounds or how they might be addressed. The purpose of this study was to address this gap in knowledge by investigating the lived experience of malignant wounds from the perspectives of those living it. In-depth interviews were conducted with patients, caregivers and nurses. The data were analysed thematically within a hermeneutic phenomenological methodology to show four themes: (i) malodour; (ii) new mode of being-in-the-world; (iii) still room for hope and (iv) enduring memories. Although this study confirmed previous findings that malodour was one of the worst aspects of malignant wounds, it was significant that the other three themes occurred in the previously largely overlooked psychosocial domain.

  7. Some applications of holographic interferometry in biomechanics

    NASA Astrophysics Data System (ADS)

    Ebbeni, Jean P. L.

    1992-03-01

    Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.

  8. The Path to Interferometry in Space

    NASA Technical Reports Server (NTRS)

    Rinehart, S. A.; Savini, G.; Holland, W.; Absil, O.; Defrere, D.; Spencer, L.; Leisawitz, D.; Rizzo, M.; Juanola-Parramon, R.; Mozurkewich, D.

    2016-01-01

    For over two decades, astronomers have considered the possibilities for interferometry in space. The first of these missions was the Space Interferometry Mission (SIM), but that was followed by missions for studying exoplanets (e.g Terrestrial Planet Finder, Darwin), and then far-infrared interferometers (e.g. the Space Infrared Interferometric Telescope, the Far-Infrared Interferometer). Unfortunately, following the cancellation of SIM, the future for space-based interferometry has been in doubt, and the interferometric community needs to reevaluate the path forward. While interferometers have strong potential for scientific discovery, there are technological developments still needed, and continued maturation of techniques is important for advocacy to the broader astronomical community. We review the status of several concepts for space-based interferometry, and look for possible synergies between missions oriented towards different science goals.

  9. The path to interferometry in space

    NASA Astrophysics Data System (ADS)

    Rinehart, S. A.; Savini, G.; Holland, W.; Absil, O.; Defrère, D.; Spencer, L.; Leisawitz, D.; Rizzo, M.; Juanola-Paramon, R.; Mozurkewich, D.

    2016-08-01

    For over two decades, astronomers have considered the possibilities for interferometry in space. The first of these missions was the Space Interferometry Mission (SIM), but that was followed by missions for studying exoplanets (e.g Terrestrial Planet Finder, Darwin), and then far-infrared interferometers (e.g. the Space Infrared Interferometric Telescope, the Far-Infrared Interferometer). Unfortunately, following the cancellation of SIM, the future for space-based interferometry has been in doubt, and the interferometric community needs to reevaluate the path forward. While interferometers have strong potential for scientific discovery, there are technological developments still needed, and continued maturation of techniques is important for advocacy to the broader astronomical community. We review the status of several concepts for space-based interferometry, and look for possible synergies between missions oriented towards different science goals.

  10. Advanced interferometry at Carl Zeiss (Summary Only)

    NASA Astrophysics Data System (ADS)

    Kuechel, Michael F.

    1992-10-01

    Research at Carl Zeiss has led to some innovative solutions in the field of optical test methods and interferometry. One example is the method of `direct measuring interferometry' (DMI), which was developed to overcome the problems of vibration and air turbulence when testing big astronomical primaries and is now the heart of the Carl Zeiss laser-interferometer DIRECT 100. Since DMI offers real-time capabilities for the wavefront evaluation, a built-in frame-memory can act as an `electronic hologram' and opens very elegant ways for in-situ correction of small residual errors, for easy aspherical testing, a very simple way of two- wavelength-interferometry, or a new discipline of time-resolved interferometry.

  11. Fringe Formation in Dual-Hologram Interferometry

    NASA Technical Reports Server (NTRS)

    Burner, A. W.

    1989-01-01

    A first order geometrical optics treatment of holograms combined with the generation of interference fringes by two point sources is used to describe reference fringe formation in non-diffuse dual-hologram interferometry.

  12. Probing atmospheric structure with infrasonic ambient noise interferometry (Invited)

    NASA Astrophysics Data System (ADS)

    Haney, M. M.; Evers, L. G.; Fricke, J.

    2010-12-01

    Ambient noise interferometry attempts to reconstruct the impulse response of a linear system undergoing excitations by a random forcing. The method has proven to be quite general, finding applications in diverse fields such as ultrasonics, helioseismology, regional and global seismology, ocean acoustics, and exploration seismology. Due to the pervasive random forcing of microbaroms, the study of atmospheric infrasound can benefit from approaches developed in the field of interferometry as well. Moreover, continuous noise sources, such as microbaroms, provide a means to quantify the strong time-dependent changes inherent in the structure of the atmosphere. For pairs of infrasonic sensors separated by distances between 1 and 15 km, direct arrivals have been observed in long-time correlations of ambient noise from stations within 3 different networks: the network operated by the Alaska Volcano Observatory, the I53US array, and the Utah 07 experiment. As in seismic ambient noise studies, these interferometric arrivals show dispersive properties characteristic of guided wave propagation. As a result, infrasonic ambient noise interferometry can provide information on the gross structure of the atmospheric boundary layer. At Fourpeaked Volcano, Alaska, a surface-based temperature inversion produced a strong waveguide between two infrasound sensors. The propagation time of the interferometric arrivals shifted over the course of several days in close correspondence with regional temperature trends at nearby meteorological stations. Independent ECMWF data confirms the existence of a temperature inversion during this time period. Analysis of 4 infrasound sensors near Park City, Utah, further demonstrates the ability of infrasonic ambient noise interferometry to retrieve guided waves between stations separated by 5 to 10 km. Among the 4 stations, we observe strong interferometric arrivals on different station pairs at different times, attesting to variable atmospheric

  13. Ethical challenges in the neonatal intensive care units: perceptions of physicians and nurses; an Iranian experience.

    PubMed

    Kadivar, Maliheh; Mosayebi, Ziba; Asghari, Fariba; Zarrini, Pari

    2015-01-01

    The challenging nature of neonatal medicine today is intensified by modern advances in intensive care and treatment of sicker neonates. These developments have caused numerous ethical issues and conflicts in ethical decision-making. The present study surveyed the challenges and dilemmas from the viewpoint of the neonatal intensive care personnel in the teaching hospitals of Tehran University of Medical Sciences (TUMS) in the capital of Iran. In this comparative cross-sectional study conducted between March 2013 and February 2014, the physicians' and nurses' perceptions of the ethical issues in neonatal intensive care units were compared. The physicians and nurses of the study hospitals were requested to complete a 36-item questionnaire after initial accommodations. The study samples consisted of 284 physicians (36%) and nurses (64%). Content validity and internal consistency calculations were used to examine the psychometric properties of the questionnaire. Data were analyzed by Pearson's correlation, t-test, ANOVA, and linear regression using SPSS v. 22. Respecting patients' rights and interactions with parents were perceived as the most challenging aspects of neonatal care. There were significant differences between sexes in the domains of the perceived challenges. According to the linear regression model, the perceived score would be reduced 0.33 per each year on the job. The results of our study showed that the most challenging issues were related to patients' rights, interactions with parents, communication and cooperation, and end of life considerations respectively. It can be concluded, therefore, that more attention should be paid to these issues in educational programs and ethics committees of hospitals.

  14. Ethical challenges in the neonatal intensive care units: perceptions of physicians and nurses; an Iranian experience

    PubMed Central

    Kadivar, Maliheh; Mosayebi, Ziba; Asghari, Fariba; Zarrini, Pari

    2015-01-01

    The challenging nature of neonatal medicine today is intensified by modern advances in intensive care and treatment of sicker neonates. These developments have caused numerous ethical issues and conflicts in ethical decision-making. The present study surveyed the challenges and dilemmas from the viewpoint of the neonatal intensive care personnel in the teaching hospitals of Tehran University of Medical Sciences (TUMS) in the capital of Iran. In this comparative cross-sectional study conducted between March 2013 and February 2014, the physicians’ and nurses’ perceptions of the ethical issues in neonatal intensive care units were compared. The physicians and nurses of the study hospitals were requested to complete a 36-item questionnaire after initial accommodations. The study samples consisted of 284 physicians (36%) and nurses (64%). Content validity and internal consistency calculations were used to examine the psychometric properties of the questionnaire. Data were analyzed by Pearson's correlation, t-test, ANOVA, and linear regression using SPSS v. 22. Respecting patients’ rights and interactions with parents were perceived as the most challenging aspects of neonatal care. There were significant differences between sexes in the domains of the perceived challenges. According to the linear regression model, the perceived score would be reduced 0.33 per each year on the job. The results of our study showed that the most challenging issues were related to patients’ rights, interactions with parents, communication and cooperation, and end of life considerations respectively. It can be concluded, therefore, that more attention should be paid to these issues in educational programs and ethics committees of hospitals. PMID:26839675

  15. Medical end-of-life decisions: experiences and attitudes of Belgian pediatric intensive care nurses.

    PubMed

    Inghelbrecht, Els; Bilsen, Johan; Pereth, Heidi; Ramet, José; Deliens, Luc

    2009-03-01

    To investigate Belgian pediatric intensive care nurses' involvement in and attitudes toward medical end-of-life decisions with a possible or certain life-shortening effect. Questionnaires were distributed to 141 nurses working in 5 of the 7 pediatric intensive care units in Belgium. Nurses were asked to recall the last child in their care whose treatment involved an end-of-life decision and to describe anonymously their involvement in the decision. Attitudes were ascertained by means of statements and a Likert scale. Questionnaires were completed by 89 nurses (63%). During the preceding 2 years, 76 (85%) had cared for at least 1 child for whom a medical end-of-life decision had been made. Nurses were involved in initiating the decision in 17% of cases, participated in decision making in 50%, and played a role in carrying out the decision in 90%. Only 6% of nurses found it always ethically wrong to hasten the death of a child by administering lethal drugs; most nurses (78%) reported they were prepared to cooperate in administering life-ending drugs in some cases. Most (89%) favored adapting the law, making life termination of children legally possible in certain cases. Belgian pediatric intensive care nurses are often involved in carrying out medical end-of-life decisions, including administration of life-ending drugs, whereas their participation in decision making is more limited. Most think that the current euthanasia law should be extended to minors so that administering life-ending drugs would be possible for terminally ill children in specific circumstances.

  16. Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory

    SciTech Connect

    Petrignani, Annemieke; Berg, Max H.; Grussie, Florian; Wolf, Andreas; Mizus, Irina I.; Zobov, Nikolai F.; Polyansky, Oleg L.; Tennyson, Jonathan; Pavanello, Michele; Adamowicz, Ludwik

    2014-12-28

    The visible spectrum of H{sub 3}{sup +} is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H{sub 3}{sup +} up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H{sub 3}{sup +} and found to be in excellent agreement, even in the region where states have been classified as chaotic.

  17. Development of a cryogenic hydrogen microjet for high-intensity, high-repetition rate experiments

    SciTech Connect

    Kim, J. B.; Göde, S.; Glenzer, S. H.

    2016-08-19

    The advent of high-intensity, high-repetition-rate lasers has led to the need for replenishing targets of interest for high energy density sciences. We describe the design and characterization of a cryogenic microjet source, which can deliver a continuous stream of liquid hydrogen with a diameter of a few microns. The jet has been imaged at 1 μm resolution by shadowgraphy with a short pulse laser. In conclusion, the pointing stability has been measured at well below a mrad, for a stable free-standing filament of solid-density hydrogen.

  18. [Plasmacoagulase-negative Staphylococcus sepsis: experience in a neonatal intensive care unit].

    PubMed

    Pérez Fernández, J M; Soler Carreras, C; Esque Ruiz, M T; Llagostera Benedico, J; Carbonell-Estrany, X

    1987-08-01

    Among 1,049 admissions in the newborn department, during 18 months, authors found 148 positive blood cultures to staphylococci epidermidis (EPN). Recovery of EPN from blood should not be dismissed as a contaminant. 11 newborn were considered to have septicemia by EPN, that means 1.04% of all admissions and 5.6% of babies admitted in intensive care. They find that catheters (100%), assisted ventilation (45.4%) and previous surgery (36.3%) are significant predisposing risk factors. Clinical and laboratory pattern was not different of other sepsis except its late onset. Two patient died. Vancomycin is considered the drug of choice.

  19. Development of a cryogenic hydrogen microjet for high-intensity, high-repetition rate experiments

    NASA Astrophysics Data System (ADS)

    Kim, J. B.; Göde, S.; Glenzer, S. H.

    2016-11-01

    The advent of high-intensity, high-repetition-rate lasers has led to the need for replenishing targets of interest for high energy density sciences. We describe the design and characterization of a cryogenic microjet source, which can deliver a continuous stream of liquid hydrogen with a diameter of a few microns. The jet has been imaged at 1 μm resolution by shadowgraphy with a short pulse laser. The pointing stability has been measured at well below a mrad, for a stable free-standing filament of solid-density hydrogen.

  20. Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory

    NASA Astrophysics Data System (ADS)

    Petrignani, Annemieke; Berg, Max H.; Grussie, Florian; Wolf, Andreas; Mizus, Irina I.; Polyansky, Oleg L.; Tennyson, Jonathan; Zobov, Nikolai F.; Pavanello, Michele; Adamowicz, Ludwik

    2014-12-01

    The visible spectrum of H3 + is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H3 + up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H3 + and found to be in excellent agreement, even in the region where states have been classified as chaotic.

  1. To feel strong in an unfamiliar situation; Patients' lived experiences of neurosurgical intensive care. A qualitative study.

    PubMed

    Mylén, Jenny; Nilsson, Maria; Berterö, Carina

    2016-02-01

    The aim of this study was to explore the lived experiences of conscious patients in neurosurgical intensive care. Data collection was performed by qualitative interviews using an interview guide. Eleven former patients, seven women and four men, were interviewed two to 14 months after discharge. The interviews were recorded and transcribed verbatim and analysed using an interpretive phenomenological approach. The analysis revealed three themes: To feel safe in an unfamiliar situation, to experience strains and limitations, and to be confirmed as a human being. These three themes culminated in the essence: To feel strong in an unfamiliar situation. Patients experienced a soothing environment where, despite strains, they felt safe being cared for in a ward with specialised medical treatment. When mental and physical strains decreased during the period of care, they experienced the ability to cope with the simplest tasks as a sign of regained identity. Patients' main experience during intensive care was security. Security along with human contact and interaction with staff and next of kin made the patients feel strengthened as human beings in an unfamiliar situation. The fact that the patients were conscious enabled them to understand their situation and to experience security. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Validation of the Land-Surface Energy Budget and Planetary Boundary Layer for Several Intensive field Experiments

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Schubert, Siegfried; Molod, Andrea; Houser, Paul R.

    1999-01-01

    Land-surface processes in a data assimilation system influence the lower troposphere and must be properly represented. With the recent incorporation of the Mosaic Land-surface Model (LSM) into the GEOS Data Assimilation System (DAS), the detailed land-surface processes require strict validation. While global data sources can identify large-scale systematic biases at the monthly timescale, the diurnal cycle is difficult to validate. Moreover, global data sets rarely include variables such as evaporation, sensible heat and soil water. Intensive field experiments, on the other hand, can provide high temporal resolution energy budget and vertical profile data for sufficiently long periods, without global coverage. Here, we evaluate the GEOS DAS against several intensive field experiments. The field experiments are First ISLSCP Field Experiment (FIFE, Kansas, summer 1987), Cabauw (as used in PILPS, Netherlands, summer 1987), Atmospheric Radiation Measurement (ARM, Southern Great Plains, winter and summer 1998) and the Surface Heat Budget of the Arctic Ocean (SHEBA, Arctic ice sheet, winter and summer 1998). The sites provide complete surface energy budget data for periods of at least one year, and some periods of vertical profiles. This comparison provides a detailed validation of the Mosaic LSM within the GEOS DAS for a variety of climatologic and geographic conditions.

  3. Measuring Close Binary Stars with Speckle Interferometry

    DTIC Science & Technology

    2014-09-01

    Measuring Close Binary Stars with Speckle Interferometry Keith T. Knox Air Force Research Laboratory ABSTRACT Speckle interferometry...Labeyrie, 1970) is a well-tested and still used method for detecting and measuring binary stars that are closer together than the width of the...orientation of the binary star system (Horch, 1996, Tokovinin, 2010). In this talk, a method for analyzing the fringes in the power spectrum will be

  4. Fringe formation in dual-hologram interferometry

    NASA Astrophysics Data System (ADS)

    Burner, A. W.

    Reference-fringe formation in nondiffuse dual-hologram interferometry is described by combining a first-order geometrical hologram treatment with interference fringes generated by two point sources. The first-order imaging relationships can be used to describe reference-fringe patterns for the geometry of the dual-hologram interferometry. The process can be completed without adjusting the two holograms when the reconstructing wavelength is less than the exposing wavelength, and the process is found to facilitate basic intereferometer adjustments.

  5. Classical Stückelberg interferometry of a nanomechanical two-mode system

    NASA Astrophysics Data System (ADS)

    Seitner, Maximilian J.; Ribeiro, Hugo; Kölbl, Johannes; Faust, Thomas; Kotthaus, Jörg P.; Weig, Eva M.

    2016-12-01

    Stückelberg interferometry is a phenomenon that has been well established for quantum-mechanical two-level systems. Here, we present classical two-mode interference of a nanomechanical two-mode system, realizing a classical analog of Stückelberg interferometry. Our experiment relies on the coherent energy exchange between two strongly coupled, high-quality factor nanomechanical resonator modes. Furthermore, we discuss an exact theoretical solution for the double-passage Stückelberg problem by expanding the established finite-time Landau-Zener single-passage solution. For the parameter regime explored in the experiment, we find that the Stückelberg return probability in the classical version of the problem formally coincides with the quantum case, which reveals the analogy of the return probabilities in the quantum-mechanical and the classical version of the problem. This result qualifies classical two-mode systems at large to simulate quantum-mechanical interferometry.

  6. An in-vacuo optical levitation trap for high-intensity laser interaction experiments with isolated microtargets

    SciTech Connect

    Price, C. J. Giltrap, S.; Stuart, N. H.; Parker, S.; Patankar, S.; Lowe, H. F.; Smith, R. A.; Donnelly, T. D.; Drew, D.; Gumbrell, E. T.

    2015-03-15

    We report on the design, construction, and characterisation of a new class of in-vacuo optical levitation trap optimised for use in high-intensity, high-energy laser interaction experiments. The system uses a focused, vertically propagating continuous wave laser beam to capture and manipulate micro-targets by photon momentum transfer at much longer working distances than commonly used by optical tweezer systems. A high speed (10 kHz) optical imaging and signal acquisition system was implemented for tracking the levitated droplets position and dynamic behaviour under atmospheric and vacuum conditions, with ±5 μm spatial resolution. Optical trapping of 10 ± 4 μm oil droplets in vacuum was demonstrated, over timescales of >1 h at extended distances of ∼40 mm from the final focusing optic. The stability of the levitated droplet was such that it would stay in alignment with a ∼7 μm irradiating beam focal spot for up to 5 min without the need for re-adjustment. The performance of the trap was assessed in a series of high-intensity (10{sup 17} W cm{sup −2}) laser experiments that measured the X-ray source size and inferred free-electron temperature of a single isolated droplet target, along with a measurement of the emitted radio-frequency pulse. These initial tests demonstrated the use of optically levitated microdroplets as a robust target platform for further high-intensity laser interaction and point source studies.

  7. Durability of targets and foils irradiated by intense heavy ion beams in experiments on synthesis of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Sagaidak, R. N.

    2017-09-01

    Durability of targets and window foils irradiated by intense heavy ion (HI) beams in the experiments on synthesis of superheavy nuclei, which are carried out in Dubna with Gas-Filled Recoil Separator (DGFRS), has been viewed in various ways. High fluxes of HI and heat generations, which are realized within relatively small areas and thicknesses of these elements of DGFRS, are inherent in such experiments. The lifetimes of the targets and window foils are estimated as the result of HI beam actions such as radiation damages, sputtering and evaporation of atoms. The most critical processes determining the durability of the targets and window foils are discussed. The processes of heat transfer due to thermal conductivity, convection and radiation are also considered from the point of view of possible ways of cooling of the elements irradiated by an intense HI beam. Temperatures of the targets and window foils as functions of time are calculated in the conditions of their pulse heating by the beam followed by radiative cooling of their surfaces. Such pulsing mode is realized in the DGFRS operation with the rotation of target and window foils irradiated by a continuous HI beam. Estimates show that radiative cooling in such conditions can be the most effective way of heat removal at the temperature of several hundred degrees. Such temperature can be reached on the surfaces of the target and window foils irradiated by HI beams at the intensity 1013 s-1.

  8. Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

    SciTech Connect

    Rosenthal, David I.; Fuller, Clifton D.; Barker, Jerry L.; Mason, Bryan M.S.; Garcia, John A. C.; Lewin, Jan S.; Holsinger, F. Christopher; Stasney, C. Richard; Frank, Steven J.; Schwartz, David L.; Morrison, William H.; Garden, Adam S.; Ang, K. Kian

    2010-06-01

    Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

  9. An in-vacuo optical levitation trap for high-intensity laser interaction experiments with isolated microtargets.

    PubMed

    Price, C J; Donnelly, T D; Giltrap, S; Stuart, N H; Parker, S; Patankar, S; Lowe, H F; Drew, D; Gumbrell, E T; Smith, R A

    2015-03-01

    We report on the design, construction, and characterisation of a new class of in-vacuo optical levitation trap optimised for use in high-intensity, high-energy laser interaction experiments. The system uses a focused, vertically propagating continuous wave laser beam to capture and manipulate micro-targets by photon momentum transfer at much longer working distances than commonly used by optical tweezer systems. A high speed (10 kHz) optical imaging and signal acquisition system was implemented for tracking the levitated droplets position and dynamic behaviour under atmospheric and vacuum conditions, with ±5 μm spatial resolution. Optical trapping of 10 ± 4 μm oil droplets in vacuum was demonstrated, over timescales of >1 h at extended distances of ∼40 mm from the final focusing optic. The stability of the levitated droplet was such that it would stay in alignment with a ∼7 μm irradiating beam focal spot for up to 5 min without the need for re-adjustment. The performance of the trap was assessed in a series of high-intensity (10(17) W cm(-2)) laser experiments that measured the X-ray source size and inferred free-electron temperature of a single isolated droplet target, along with a measurement of the emitted radio-frequency pulse. These initial tests demonstrated the use of optically levitated microdroplets as a robust target platform for further high-intensity laser interaction and point source studies.

  10. Experiment and simulation of novel liquid crystal plasma mirrors for high contrast, intense laser pulses

    DOE PAGES

    Poole, P. L.; Krygier, A.; Cochran, G. E.; ...

    2016-08-25

    Here, we describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in-situ. We also present novel particle-in-cell simulations that for the first time incorporate multiphoton ionization and dielectric models that are necessary for describing plasma mirrors. Dielectric plasma mirrors are a crucial component for high intensity laser applications such as ion acceleration and solid target high harmonic generation because they greatly improve pulse contrast. We use the liquid crystal 8CB and introduce an innovative dynamic film formation device that can tune the film thickness so that it acts as its own antireflection coating.more » Films can be formed at a prolonged, high repetition rate without the need for subsequent realignment. High intensity reflectance above 75% and low-field reflectance below 0.2% are demonstrated, as well as initial ion acceleration experimental results that demonstrate increased ion energy and yield on shots cleaned with these plasma mirrors.« less

  11. [Experience with flash-evoked visual potentials in unconscious patients in the neurologic intensive care station].

    PubMed

    Krieger, D; Adams, H P; Hacke, W

    1991-12-01

    Evoked potential monitoring has become a widely used procedure in the evaluation of stuporous patients on neurological intensive care units. Currently BAEP and SEP are preferentially employed. VEP monitoring is a relatively uncommon procedure, because late evoked potentials tend to be relatively unstable, varying in amplitude to a moderate extend from changes of temperature, drugs, attention and the level of consciousness. A valuable approach of VEP monitoring on intensive care units are structures of the visual system at risk in vascular disease of the vertebrobasilar system or during evaluated intracranial pressure (EIP). This study uses the data of 20 stuporous patients presenting with either intracranial mass lesions or vascular diseases of the vertebrobasilar system and 20 control persons. Light emitting diode (LED)-VEP are compared with checkerboard stimulation in control persons using the technique of cross-correlation. The comparison of the control group with patients using LED-VEP allows definition of limits for normal variation as a base for identification of significant changes. Despite methodical restrictions of LED-VEP, our results are in favour of serial studies in patients with EIP. There are no corresponding findings in LED-VEP and vascular lesions of the retrochiasmatic visual system.

  12. Impact of Clinical Pharmacist on the Pediatric Intensive Care Practice: An 11-Year Tertiary Center Experience.

    PubMed

    Tripathi, Sandeep; Crabtree, Heidi M; Fryer, Karen R; Graner, Kevin K; Arteaga, Grace M

    2015-01-01

    With increasing complexity of critical care medicine comes an increasing need for multidisciplinary involvement in care. In many institutions, pharmacists are an integral part of this team, but long-term data on the interventions performed by pharmacists and their effects on patient care and outcomes are limited. We aimed to describe the role of pediatric clinical pharmacists in pediatric intensive care unit (PICU) practice. We retrospectively reviewed the records of pharmacy interventions in the PICU at the Mayo Clinic in Rochester, Minnesota, from 2003-2013, with a distinct period of increased pharmacist presence in the PICU from 2008 onward. We compared demographic and outcome data on patients who did and who did not have pharmacy interventions during 2 periods (2003-2007 and 2008-2013). We identified 27,773 total interventions by pharmacists during the 11-year period, of which 79.8% were accepted by the clinical team. These interventions were made on 10,963 unique PICU admissions and prevented 5867 order entry errors. Pharmacists' interventions increased year over year, including a significant change in 2008. Patients who required pharmacy involvement were younger, sicker, and had longer intensive care unit, hospital, and ventilator duration. Average central line infections and central line entry rates decreased significantly over the study period. Increased pharmacist presence in the PICU is associated with increased interventions and prevention of adverse drug events. Pharmacist participation during rounds and order entry substantially improved the care of critically sick children and should be encouraged.

  13. A 10-year experience with major burns from a non-burn intensive care unit.

    PubMed

    Ibarra Estrada, Miguel Ángel; Chávez Peña, Quetzalcóatl; García Guardado, Dante Ismael; López Pulgarín, José Arnulfo; Aguirre Avalos, Guadalupe; Corona Jiménez, Federico

    2014-09-01

    The aim of this study was to review clinical data and outcomes of patients with burns in a Mexican non-burn intensive care unit (ICU). We did a retrospective analysis of our single-centre database of burn patients admitted to the ICU in the Hospital Civil Fray Antonio Alcalde (University Hospital). The sample was divided for analysis into two groups according to the outcome 'death' or 'discharge' from ICU. Overall mortality was 58.2%, without a decreasing trend in mortality rates through the years. We identified the presence of third-degree burns (odds ratio (OR) 1.5, p=0.003), and >49% total burned surface area (TBSA; OR 3.3, p≤0.001) was associated with mortality. Mean age was higher in deceased patients (38.2 years vs. 31.3 years, p=0.003) as was the TBSA (62.8% vs. 36.4%, p≤0.001). At multivariate analysis, inhalation injury was not associated with increased mortality, but it was with more mechanical ventilation days. Early surgical debridement/cleansing was performed in most patients; however, the mean of the procedures was 1.7 per patient in both groups. We identified significant factors associated with mortality. These variables and prognosis from non-burn ICUs differ broadly compared with burn intensive care units (BICUs); thus, more structured, multidisciplinary and specialised treatment strategies are still needed. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  14. An experimental study of nonclassical effects in two-photon interferometry

    NASA Astrophysics Data System (ADS)

    Liang, Junlin

    Two-photon interferometry is a relatively new field with applications ranging from precise measurements of optical phase shifts to fundamental tests of quantum mechanics. In contrast to conventional single-photon interferometry, two-photon interferometry typically involves measuring correlations between two detectors placed in two different output ports of an interferometer. Of particular interest is two-photon interferometry with entangled photon pairs, in which case it is often possible to observe effects that are not possible with classical fields. Because these entanglement effects are becoming increasingly important in Quantum Information Processing (QIP) applications, there is currently a strong need for further exploration of new ideas, basic physics, and experimental techniques of two-photon interferometry. Contained herein are the results of three new two-photon interferometry experiments using entangled photon pairs produced by a Type-I Parametric Down-Conversion (PDC) source. In the first experiment, we demonstrate a new technique for compensating for two-photon interferometer beamsplitter asymmetries by manipulating the polarization degree of freedom in the system. Roughly speaking, projective polarization measurements are used to re-balance the magnitude of various two-photon amplitudes that were made distinguishable by non-ideal refection and transmission coefficients of a key beamsplitter. In the second experiment, we utilize a short coherence-length continuous-wave (CW) PDC pump laser to explore two-photon interferometry in a new intermediate regime between the more familiar extremal cases which use either a long coherence-length CW pump or an ultra-short pulsed pump laser. These results provide new insight into the role of PDC pump coherence in two-photon interferometry. Finally, we use two-photon interferometry to experimentally investigate entangled "photon holes", which is a new form of entanglement that arises from the correlated absence of

  15. The Michelson Interferometry Summer School Program

    NASA Astrophysics Data System (ADS)

    Lawson, P. R.; Danner, R.

    2001-05-01

    The Michelson Interferometry Summer Schools exists to support the scientific community in building expertise in optical and infrared long-baseline interferometry. The lectures emphasize the fundamentals of astronomical interferometry, including the engineering and design of interferometers, the astrophysical potential of current and future instruments, and methods of observation, data reduction, and interpretation. The schools engage speakers from the interferometry community both in the United States and overseas, and seek to provide opportunities not only to teach but for students to interact with a broad range of specialists in the field. The schools followed on initially from the Workshop on Optical/IR Interferometry organized by USNO and JPL in 1998, and were then shaped into a cycle of three separate schools from 1999 to 2001 (engineering, astrophysics, data reduction). The current status and future plans for the schools will be described. The schools are funded through NASA's Origins Program and the Space Interferometry mission at the Jet Propulsion Laboratory with additional support from participating groups.

  16. Backreflection diagnostics for ultra-intense laser plasma experiments based on frequency resolved optical gating

    NASA Astrophysics Data System (ADS)

    Wagner, F.; Hornung, J.; Schmidt, C.; Eckhardt, M.; Roth, M.; Stöhlker, T.; Bagnoud, V.

    2017-02-01

    We report on the development and implementation of a time resolved backscatter diagnostics for high power laser plasma experiments at the petawatt-class laser facility PHELIX. Pulses that are backscattered or reflected from overcritical plasmas are characterized spectrally and temporally resolved using a specially designed second harmonic generation frequency resolved optical gating system. The diagnostics meets the requirements made by typical experiments, i.e., a spectral bandwidth of more than 30 nm with sub-nanometer resolution and a temporal window of 10 ps with 50 fs temporal resolution. The diagnostics is permanently installed at the PHELIX target area and can be used to study effects such as laser-hole boring or relativistic self-phase-modulation which are important features of laser-driven particle acceleration experiments.

  17. Picosecond X-ray Laser Interferometry for Probing Dense Laser-Produced Plasmas

    NASA Astrophysics Data System (ADS)

    Dunn, James; Smith, Raymond F.; Filevich, Jorge; Rocca, Jorge J.; Moon, Stephen J.; Nilsen, Joseph; Shlyaptsev, Vyacheslav N.; Keenan, Roisin; Ng, Andrew; Hunter, James R.; Marconi, Mario. C.

    2003-10-01

    The development of compact, x-ray laser (XRL) sources has great potential to advance interferometric techniques to shorter wavelengths for probing dense, rapidly changing, laser-heated plasmas. The use of soft x-rays has many advantages over optical or UV wavelength probes including greatly reduced refraction and lower absorption within the plasma. Another advantage when coupled with a short probe pulse duration, is the achievement of sub-micron spatial resolution close to the target surface to make precise measurements in the highest density region with negligible plasma motion blurring. This makes x-ray laser interferometry a unique tool for studying high density plasmas giving new information about the underlying physical processes and allowing the study of new plasma regimes. We describe precision interferometric characterization experiments using the picosecond, 14.7 nm x-ray laser source generated on the Compact Multipulse Terawatt (COMET) laser facilty at LLNL together with the Mach-Zehnder type Diffraction Grating Interferometer (DGI) designed and built at Colorado State University. A review of the results from dense, mm-scale line focus plasma experiments will be described with detailed comparisons to 1-, 1.5- and 2-D hydrodynamic simulations. Ongoing experiments on smaller spot focus high intensity plasmas will be discussed.

  18. Secondary desertification due to salinization of intensively irrigated lands: The Israeli experience.

    PubMed

    Banin, A; Fish, A

    1995-01-01

    Secondary salinization of intensively irrigated lands is an increasingly alarming redesertification process experienced in many irrigated regions of the developed countries. The major cause is a profound interference in the geochemical/salt balances of irrigated regions. A case-in-point is the recent salinization of the Yizre'el Valley, a 20,000 ha intensively irrigated region in Israel. The extremely intensive and advanced agroecosystem developed in the region since the 1940s included pumping and importing irrigation water by the National Water Carrier, large-scale reclamation and reuse of municipal sewage water, winter flood impoundment in reservoirs for summer irrigation, and cloud seeding to enhance rainfall. Modern irrigation methods were applied, including sprinkler, trickle, moving-line, and center-pivot systems. Water use efficiency at any level was very high. Nevertheless, large-scale salinization of regional water resources and many fields had developed in the mid-1980s. Reconstructing and evaluating the water and salt balances of the Yizre'el Valley (using Cl as the representative salt constituent) shows that as water use in the valley increased to about 60 million m(3) per year, the importing of soluble salts by water totaled 15,000 tons of Cl per year. Recirculated salt - salt picked up by impounded surface water and applied to fields - increased significantly and in the late 1980s amounted to more than 9,000 tons Cl per year. The source of recirculated salts was the accumulated salts in soils and in the shallow aquifer in the valley, which were leached by floodwater or drained or infiltrated into reservoirs, grossly and adversely affecting water quality. Analysis of the Yizre'el Valley's case points to the utmost importance of maintaining the geochemical balances in addition to increasing irrigation efficiency. An irrigated region may achieve geochemical balance by the following means: limiting the extent of irrigated areas, developing a well

  19. Caring for newborns in the presence of their parents: the experience of nurses in the neonatal intensive care unit.

    PubMed

    Merighi, Miriam Aparecida Barbosa; de Jesus, Maria Cristina Pinto; Santin, Karine Ribeiro; de Oliveira, Deíse Moura

    2011-01-01

    The nurse has a key role in involving parents in the care of newborns in the neonatal intensive care unit. The aim of this study was to comprehend how the nurses experience the care provided to newborns in the presence of the parents. This is a qualitative study using social phenomenology, with the participation of seven nurses, interviewed between January and February 2009. The nurses perceived the needs of parents; had positive expectations regarding the care provided and acknowledge themselves to be the link between them, helping them to live with the hospitalized child. However, in emergencies, the nurses had difficulties in caring for the neonate in the presence of the parents. The nurses positively evaluated the presence of parents in the neonatal intensive care unit, involving them permanently in the care of the newborn. The study evokes the emergence of a care context (nurse/neonate/parents) that precedes the proximity between the subjects and the demands presented by them.

  20. Phase-Doppler interferometry with probe-to-droplet size ratios less than unity. II. Application of the technique.

    PubMed

    Strakey, P A; Talley, D G; Sankar, S V; Bachalo, W D

    2000-08-01

    Practical limitations associated with the use of small probe volumes with respect to the droplet size that is being measured by the phase-Doppler interferometry technique are discussed. An intensity-validation scheme and corresponding probe volume correction factor have been developed that reject trajectory errors and account for the rejections in calculation of the probe cross-sectional area. The intensity-validation scheme also provides a tractable method of setting the photomultiplier tube gain and laser power. Volume flux measurements in dilute sprays have shown a significant improvement over those made by standard phase-Doppler interferometry techniques at small beam waist/droplet size ratios.

  1. Digital scrapbooking as a standard of care in neonatal intensive care units: initial experience.

    PubMed

    Subhani, Muhammad T; Kanwal, Ifrah

    2012-01-01

    In this article, we describe a digital photo scrapbooking project as a standard of care for the parents of infants admitted in a neonatal intensive care unit (NICU). Photographs were taken from birth until discharge or expiry at special moments during the infant's hospitalization and used to create a digital scrapbook with daily notes by the parents. The scrapbook and original photos were provided on a CD at discharge or at expiry. Parents and their families unanimously appreciated the photos and the opportunity to record their thoughts, and considered the CDs as a lifetime treasure. Digital photo journaling could be implemented as a standard of care at other institutions with a commitment from the nursing and ancillary staff of the NICU and labor and delivery department, with possible support from volunteers.

  2. Blue Intensity Experiments from around the World: The State of the "Art"

    NASA Astrophysics Data System (ADS)

    Wilson, Rob

    2017-04-01

    Latewood maximum density (MXD) has been shown through many studies to be an important tree-ring variable for dendroclimatology. However, as only a few laboratories have the facilities to measure this proxy, relatively few long (> 800 years) density chronologies exist. Blue Intensity (BI), a relatively new TR variable, has been shown to measure similar density-like properties as MXD, but can be measured at a fraction of the cost using standard flatbed scanners and off the shelf software packages. However, use of BI is still very much in an early developmental phase and few published dendroclimatic studies have actually used it. There remains much experimentation to fully explore the strengths and limitations of BI for dendroclimatology. In this presentation I present a range of results from several BI based studies from NW Europe, the Pyrenees, Gulf of Alaska and Australasia focusing particularly on the potential for extracting low frequency climate information.

  3. Assessing the Performance of a Medical Intensive Care Unit: A 5-year single-center Experience

    PubMed Central

    Anushiravani, Amir; Masoompour, Seyed Masoom

    2017-01-01

    Patient care in the Intensive Care Unit (ICU) is complex and expensive, serving to provide optimal outcome as well as the adequate use of resources. Our objective was to determine variables associated with admission practices, processes of care, and clinical outcomes for critically ill patients. Admission records of a 10-bed ICU were gathered during a 5-year period. Variables such as average length of stay, bed turnover, bed occupancy rate, and turnover interval were evaluated. Of the 1719 patients evaluated, 54% were men. Mortality was highest between 10 pm and 2 am. There was no significant difference in ICU mortality during different days of the week. We showed that nonoffice hour admissions were not associated with poorer clinical outcomes, and significant differences in ICU mortality and ICU length of stay were not seen. Moreover, hospital mortality rates were not significantly higher for patients admitted to our ICU on weekends, at nights, or any day of the week. PMID:28400688

  4. Phonon Counting and Intensity Interferometry of a Nanomechanical Resonator

    DTIC Science & Technology

    2014-10-04

    Fabry - Perot fil- ters with bandwidth of 50 MHz and free spectral range of 20 GHz (see Fig. 1d). The single photon detectors are fiber-coupled, WSi...through a series of narrowband tunable Fabry - Perot filters (∼ 50 MHz bandwidth, ∼ 20 GHz free-spectral range) in order to reject the pump frequency...detection correlation function. Since the pump laser is tuned to a motional side- band during the phonon counting measurement, the two Fabry - Perot filters

  5. A numerical field experiment approach for determining probabilities of microburst intensity

    NASA Technical Reports Server (NTRS)

    Droegemeier, Kelvin K.; Zweifel, Terry

    1992-01-01

    Several investigators had determined that some atmospheric parameters were related to the formation and severity of microbursts. For example, Caracena pointed out the relationship between a dry adiabatic lapse rate and microbursts in 'The crash of Delta Flight 191 at Dallas-Fort Worth international airport'. These early investigations led to the idea that numeric modeling of microbursts with varying atmospheric parameters might define 'signatures' that could lead to determining the probability of microburst intensity. The idea was that, by using already available sensors (such as static air temperature, pressure altitude, and radar reflectivity) onboard an aircraft, a reliable prediction of microburst existence and intensity could be formed. Such data could be used to create an 'expert meteorologist' using either artificial intelligence or other techniques that could be used in either reactive or look-ahead systems to vary sensitivity thresholds and coordinate the inputs from different detecting systems. To this end, Honeywell contracted to have the microburst simulations run. The questions to be addressed were the following: using the sensor set available to the aircraft (e.g. temperature, radar reflectivity, etc.), can we calculate the probability that (1) a microburst could be formed? and (2) that the resultant winds would be of sufficient magnitude to threaten the aircraft? Over a two year period, a data set of 1800 microburst simulations was accumulated. Verification of the microburst simulation was obtained using the results of other independent researchers and actual comparison to microburst events in Orlando and Denver. Some of the results from the simulation have already been incorporated into Honeywell's Windshear Detection and Guidance System with excellent results. Various aspects of this investigation are presented in viewgraph form.

  6. The Syrian civil war: The experience of the Surgical Intensive Care Units

    PubMed Central

    Ozdogan, Hatice Kaya; Karateke, Faruk; Ozdogan, Mehmet; Cetinalp, Sibel; Ozyazici, Sefa; Gezercan, Yurdal; Okten, Ali Ihsan; Celik, Muge; Satar, Salim

    2016-01-01

    Objective: Since the civilian war in Syria began, thousands of seriously injured trauma patients from Syria were brought to Turkey for emergency operations and/or postoperative intensive care. The aim of this study was to present the demographics and clinical features of the wounded patients in Syrian civil war admitted to the surgical intensive care units in a tertiary care centre. Methods: The records of 80 trauma patients admitted to the Anaesthesia, General Surgery and Neurosurgery ICUs between June 1, 2012 and July 15, 2014 were included in the study. The data were reviewed regarding the demographics, time of presentation, place of reference, Acute Physiology and Chronic Health Evaluation II (APACHE II) score and Injury Severity Score (ISS), surgical procedures, complications, length of stay and mortality. Results: A total of 80 wounded patients (70 males and 10 females) with a mean age of 28.7 years were admitted to surgical ICUs. The most frequent cause of injury was gunshot injury. The mean time interval between the occurrence of injury and time of admission was 2.87 days. Mean ISS score on admission was 21, and mean APACHE II score was 15.7. APACHE II scores of non-survivors were significantly increased compared with those of survivors (P=0.001). No significant differences was found in the age, ISS, time interval before admission, length of stay in ICU, rate of surgery before or after admission. Conclusion: The most important factor affecting mortality in this particular trauma-ICU patient population from Syrian civil war was the physiological condition of patients on admission. Rapid transport and effective initial and on-road resuscitation are critical in decreasing the mortality rate in civil wars and military conflicts. PMID:27375683

  7. Blue Intensity based experiments for reconstructing North Pacific temperatures along the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Wilson, Rob; D'Arrigo, Rosanne; Andreu-Hayles, Laia; Oelkers, Rose; Wiles, Greg; Anchukaitis, Kevin; Davi, Nicole

    2017-04-01

    The Gulf of Alaska (GOA) is highly sensitive to the variability of the North Pacific climate system. Ring-width (RW) records from the GOA have yielded a valuable long-term perspective for North Pacific changes on decadal to longer time scales in previous studies, but can be less robust on interannual time scales due to autocorrelation and other factors. Similar to maximum latewood density (MXD), the novel Blue Intensity (BI) parameter has recently been shown to correlate strongly with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI is much less expensive and labor intensive to generate than MXD, it has much value for future tree-ring studies in the GOA where few MXD records have been developed. Here we highlight the potential for improvement of reconstruction models using various combinations of RW and BI-related parameters (latewood BI and delta BI) measured from eight hemlock (Tsuga mertensiana) sites along the GOA. This is the first such study for the hemlock genus using BI data. We find that a combined experimental model using RW, delta BI and latewood BI best reflects inter-annual to multi-decadal temperature variability for the North Pacific sector, particularly during the warm-season months. A resulting test reconstruction (1792-1989 CE) of GOA CRUT 3.24 land JJAS temperatures (57-60°N/154-134°W) is significantly improved over that based on RW alone (58% vs 36% variance explained). Significant validation is also found with 19th century temperature data from Sitka, Alaska and using the BEST gridded data product. We therefore find that BI has considerable potential to become a sensitive, readily accessible alternative proxy for understanding past ocean-atmosphere variability in the GOA and elsewhere around the globe. A key need in furthering the utility of BI as a proxy is experimentation in the extraction of lower frequency variability.

  8. [Functional echocardiography in neonatal intensive care: 1 year experience in a unit in Spain].

    PubMed

    Corredera, A; Rodríguez, M J; Arévalo, P; Llorente, B; Moro, M; Arruza, L

    2014-09-01

    Several publications highlight the usefulness of functional echocardiography (FnECHO) in neonatal intensive care. Data is lacking on its use in units neonatal in Spain. To evaluate frequency of use, patient characteristics, indications, measurements, and impact on patient management of FnECHO in a neonatal intensive care unit (NICU) in Spain over a 1 year period. A retrospective study conducted in NICU patients during 1 year. gestational age, birthweight, admission criteria, days of life at examination, indication for FnECHO, parameters assessed, and treatment modifications. 168 echocardiographic studies were performed in 50 patients (mean 3,4. SD 2,83). The most frequent indication was patent ductus (PDA) assessment (58.3%), followed by hemodynamic instability (22.2%). The results of FnECHO modified treatment in 62 cases (36.9%). In 17.4% of them treatment with ibuprofen was initiated, and in 1.2% it was discontinued. In 10.8% of the cases, the results of FnECHO modified hemodynamic support. Echocardiographic evaluation included: assessment of presence/hemodynamic significance of PDA (100%); myocardiac function: ejection fraction/shortening fraction (EF/SF) 23.8%, left ventricular output 24.4%, right ventricular output 21.4%, systemic blood flow 42.3%; and signs of pulmonary hypertension 7.7%. FnECHO is frequently used in the NICU, and in many cases it guides treatment. PDA assessment and hemodynamic instability are the most frequent indications. It still needs to be elucidated if the use of FnECHO modifies patient outcomes. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  9. Impact of Clinical Pharmacist on the Pediatric Intensive Care Practice: An 11-Year Tertiary Center Experience

    PubMed Central

    Crabtree, Heidi M.; Fryer, Karen R.; Graner, Kevin K.; Arteaga, Grace M.

    2015-01-01

    OBJECTIVES: With increasing complexity of critical care medicine comes an increasing need for multidisciplinary involvement in care. In many institutions, pharmacists are an integral part of this team, but long-term data on the interventions performed by pharmacists and their effects on patient care and outcomes are limited. We aimed to describe the role of pediatric clinical pharmacists in pediatric intensive care unit (PICU) practice. METHODS: We retrospectively reviewed the records of pharmacy interventions in the PICU at the Mayo Clinic in Rochester, Minnesota, from 2003-2013, with a distinct period of increased pharmacist presence in the PICU from 2008 onward. We compared demographic and outcome data on patients who did and who did not have pharmacy interventions during 2 periods (2003–2007 and 2008–2013). RESULTS: We identified 27,773 total interventions by pharmacists during the 11-year period, of which 79.8% were accepted by the clinical team. These interventions were made on 10,963 unique PICU admissions and prevented 5867 order entry errors. Pharmacists' interventions increased year over year, including a significant change in 2008. Patients who required pharmacy involvement were younger, sicker, and had longer intensive care unit, hospital, and ventilator duration. Average central line infections and central line entry rates decreased significantly over the study period. CONCLUSIONS: Increased pharmacist presence in the PICU is associated with increased interventions and prevention of adverse drug events. Pharmacist participation during rounds and order entry substantially improved the care of critically sick children and should be encouraged. PMID:26380569

  10. The Syrian civil war: The experience of the Surgical Intensive Care Units.

    PubMed

    Ozdogan, Hatice Kaya; Karateke, Faruk; Ozdogan, Mehmet; Cetinalp, Sibel; Ozyazici, Sefa; Gezercan, Yurdal; Okten, Ali Ihsan; Celik, Muge; Satar, Salim

    2016-01-01

    Since the civilian war in Syria began, thousands of seriously injured trauma patients from Syria were brought to Turkey for emergency operations and/or postoperative intensive care. The aim of this study was to present the demographics and clinical features of the wounded patients in Syrian civil war admitted to the surgical intensive care units in a tertiary care centre. The records of 80 trauma patients admitted to the Anaesthesia, General Surgery and Neurosurgery ICUs between June 1, 2012 and July 15, 2014 were included in the study. The data were reviewed regarding the demographics, time of presentation, place of reference, Acute Physiology and Chronic Health Evaluation II (APACHE II) score and Injury Severity Score (ISS), surgical procedures, complications, length of stay and mortality. A total of 80 wounded patients (70 males and 10 females) with a mean age of 28.7 years were admitted to surgical ICUs. The most frequent cause of injury was gunshot injury. The mean time interval between the occurrence of injury and time of admission was 2.87 days. Mean ISS score on admission was 21, and mean APACHE II score was 15.7. APACHE II scores of non-survivors were significantly increased compared with those of survivors (P=0.001). No significant differences was found in the age, ISS, time interval before admission, length of stay in ICU, rate of surgery before or after admission. The most important factor affecting mortality in this particular trauma-ICU patient population from Syrian civil war was the physiological condition of patients on admission. Rapid transport and effective initial and on-road resuscitation are critical in decreasing the mortality rate in civil wars and military conflicts.

  11. Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement.

    PubMed

    Le Floch, Sébastien; Salvadé, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

    2010-02-01

    We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of +/- 50 microm for a 1 ms acquisition time.

  12. Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement

    SciTech Connect

    Le Floch, Sebastien; Salvade, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

    2010-02-01

    We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of {+-} 50 {mu}m for a 1 ms acquisition time.

  13. Complex amplitude correlation for compensation of large in-plane motion in digital speckle pattern interferometry

    SciTech Connect

    Svanbro, Angelica; Sjoedahl, Mikael

    2006-12-01

    The use of complex amplitude correlation to compensate for large in-plane motion in digital speckle pattern interferometry is investigated. The result is compared with experiments where digital speckle photography (DSP) is used for compensation. An advantage of using complex amplitude correlation instead of intensity correlation (as in DSP) is that the phase change describing the deformation is retrieved directly from the correlation peak, and there is no need to compensate for the large movement and then use the interferometric algorithms. A discovered drawback of this method is that the correlation values drop quickly if a phase gradient larger than {pi} is present in the subimages used for cross correlation. This means that, for the complex amplitude correlation to be used, the size of the subimages must be well chosen or a third parameter in the cross-correlation algorithm that compensates for the phase variation is needed.Correlation values and wrapped phase maps from the two techniques (intensity and complex amplitude correlation) are presented.

  14. Measurement of Opening Displacement of Single and Bifurcated Notches by Moiré Interferometry

    NASA Astrophysics Data System (ADS)

    Suzuki, S.; Miyashita, T.; Kimura, H.; Nishikita, S.

    2010-06-01

    Static experiments are performed to confirm the COD method that is the only method to measure the energy release rate of fast propagating cracks just after bifurcation. The crack opening displacement (COD) of the mother cracks of bifurcated cracks is measured in static condition by Moiré interferometry. Thin notches are used instead of cracks. The bifurcation angle is 13.5 degrees that is the same as the angle of bifurcation of fast propagating cracks in PMMA. The measured CODs are proportional to the square root of the distance from the nominal tip of the mother notch. Stress intensity factor of the bifurcated notch is obtained from the measured CODs through the formula of the COD of single cracks. The experimental results say that the stress intensity factor of a bifurcated crack has the same value as that of the single crack whose length is the same as that of the bifurcated crack. This is caused by the small bifurcation angle of 13.5 degrees. It is concluded that the COD method is correct to measure the energy release rate of rapidly bifurcating cracks.

  15. Life's Little Problems: An Intensive Look at the Daily Experiences of Young Children. Informal Paper.

    ERIC Educational Resources Information Center

    Wolfson, Bernice J.; Jackson, Philip W.

    Three studies were conducted in an initial attempt to investigate the psychological importance of trivial everyday frustrations encountered by preschool children. Study 1 analyzed the frequency and quality of experiences that could be interpreted as interfering in some way with children's natural pursuit of their desires. In a nursery school…

  16. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Treesearch

    M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

  17. Power and Flow Experience in Time-Intensive Business Simulation Game

    ERIC Educational Resources Information Center

    Kiili, Kristian; Lainema, Timo

    2010-01-01

    Power is an influential component of social interaction and there are reasons for thinking that it may have important effects both on decision-making and psychological and interpersonal processes. The aim of this paper was to study the relations between the feeling of power, decision-making and flow experience in a collaborative business…

  18. Intensity and Passion: On Musical Experience, Layers of Meaning, and Stages

    ERIC Educational Resources Information Center

    Varkøy, Øivind; Westby, Inger Anne

    2014-01-01

    In this article, the authors link the discussion of differing musical experiences to Frede V. Nielsen's exploration of music as a multifarious universe of meaning, which, in encounter with the listener's receptive consciousness, presents different layers of musical meaning. The focal point of the article is that which Nielsen refers to…

  19. Intensity and Passion: On Musical Experience, Layers of Meaning, and Stages

    ERIC Educational Resources Information Center

    Varkøy, Øivind; Westby, Inger Anne

    2014-01-01

    In this article, the authors link the discussion of differing musical experiences to Frede V. Nielsen's exploration of music as a multifarious universe of meaning, which, in encounter with the listener's receptive consciousness, presents different layers of musical meaning. The focal point of the article is that which Nielsen refers to…

  20. Low intensity interventions for Obsessive-Compulsive Disorder (OCD): a qualitative study of mental health practitioner experiences.

    PubMed

    Gellatly, Judith; Pedley, Rebecca; Molloy, Christine; Butler, Jennifer; Lovell, Karina; Bee, Penny

    2017-02-22

    Obsessive-compulsive disorder (OCD) is a debilitating mental health disorder that can substantially impact upon quality of life and everyday functioning. Guidelines recommend pharmacological and psychological treatments, using a cognitive behaviour therapy approach (CBT) including exposure and response prevention, but access has generally been poor. Low intensity psychological interventions have been advocated. The evidence base for these interventions is emerging but there is a paucity of information regarding practitioners' perceptions and experiences of supporting individuals with OCD using this approach. Qualitative interviews were undertaken with psychological wellbeing practitioners (PWPs) (n = 20) delivering low intensity psychological interventions for adults with OCD within the context of a large pragmatic effectiveness trial. Interviews explored the feasibility and acceptability of delivering two interventions; guided self-help and supported computerised cognitive behaviour therapy (cCBT), within Improving Access to Psychological Therapies (IAPT) services in NHS Trusts. Interviews were recorded with consent, transcribed and analysed using thematic analysis. PWPs acknowledged the benefits of low intensity psychological interventions for individuals experiencing OCD symptoms on an individual and population level. Offering low intensity support provided was perceived to have the opportunity to overcome existing service barriers to access treatment, improve patient choice and flexibility. Professional and service relevant issues were also recognised including self-beliefs about supporting people with OCD and personal training needs. Challenges to implementation were recognised in relation to practitioner resistance and intervention delivery technical complications. This study has provided insight into the implementation of new low intensity approaches to the management of OCD within existing mental health services. Benefits from a practitioner, service

  1. General Relativistic Effects in Atom Interferometry

    SciTech Connect

    Dimopoulos, Savas; Graham, Peter W.; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.

    2008-03-17

    Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.

  2. Ball bearing measurement with white light interferometry

    NASA Astrophysics Data System (ADS)

    Schmit, Joanna; Han, Sen; Novak, Erik

    2009-06-01

    Requirements on high-performance of ball bearings in terms of the loads they experience and their reliability are increasing as the automotive, aerospace, and power generation industries look to cut costs, reduce emissions, and improve efficiency. Most bearings are evaluated with a stylus profiler or with a bright field scopes or microscopes for form, roughness, and defect classification. Two-dimensional stylus measurements captures only very localized surface profiles unless multiple scans are performed which slow the measurement time unacceptably; this leads to inadequate sampling and sometimes greatly varying results based on location and directionality of the line scan. Bright field microscopes deliver only the lateral information about defects but not their depth, volume or surface roughness. White light interferometry can be very successfully utilized in the measurement of full field form, roughness and defect detection and is gaining adoption. They provide rapid, accurate, three-dimensional imaging compatible with the newly developed ISO 3D surface parameters which are expected to rapidly displace traditional 2D metrics. These surface parameters allow for better characterization of surface structure and better understanding of the production process and bearing and race wear. New 3D filtering techniques allow effective separation of form, waviness, and roughness for highly accurate and repeatable bearing qualification.

  3. Experimental demonstration of deep frequency modulation interferometry.

    PubMed

    Isleif, Katharina-Sophie; Gerberding, Oliver; Schwarze, Thomas S; Mehmet, Moritz; Heinzel, Gerhard; Cervantes, Felipe Guzmán

    2016-01-25

    Experiments for space and ground-based gravitational wave detectors often require a large dynamic range interferometric position readout of test masses with 1 pm/√Hz precision over long time scales. Heterodyne interferometer schemes that achieve such precisions are available, but they require complex optical set-ups, limiting their scalability for multiple channels. This article presents the first experimental results on deep frequency modulation interferometry, a new technique that combines sinusoidal laser frequency modulation in unequal arm length interferometers with a non-linear fit algorithm. We have tested the technique in a Michelson and a Mach-Zehnder Interferometer topology, respectively, demonstrated continuous phase tracking of a moving mirror and achieved a performance equivalent to a displacement sensitivity of 250 pm/Hz at 1 mHz between the phase measurements of two photodetectors monitoring the same optical signal. By performing time series fitting of the extracted interference signals, we measured that the linearity of the laser frequency modulation is on the order of 2% for the laser source used.

  4. Synchrotron Light Interferometry at Jefferson Lab

    SciTech Connect

    Arne Freyberger; Pavel Chevtsov; Anthony Day; William Hicks

    2004-07-01

    The hyper-nuclear physics program at JLAB requires an upper limit on the RMS momentum spread of {delta}p/p < 3 x 10{sup -5}. The momentum spread is determined by measuring the beam width at a dispersive location (D {approx} 4m) in the transport line to the experimental halls. Ignoring the epsilon-beta contribution to the intrinsic beam size, this momentum spread corresponds to an upper bound on the beam width of {sigma}{sub beam} < 120 {micro}m. Typical techniques to measure and monitor the beam size are either invasive or do not have the resolution to measure such small beam sizes. Using interferometry of the synchrotron light produced in the dispersive bend, the resolution of the optical system can be made very small. The non-invasive nature of this measurement allows continuous monitoring of the momentum spread. Two synchrotron light interferometers have been built and installed at JLAB, one each in the Hall-A and Hall-C transport lines. The devices operate over a beam current range from 20 {micro}A to 120 {micro}A and have a spatial resolution of 10um. The structure of the interferometers, the experience gained during its installation, beam measurements and momentum spread stability are presented. The dependence of the measured momentum spread on beam current will be presented.

  5. [Intensive care and home artificial ventilation. How do nurses experience artificial respiratory care in the home of patients?].

    PubMed

    Gödecke, Christiane; Kohlen, Helen

    2013-04-01

    In Germany, the number of patients who receive artificial respiration in their own home is increasing. One reason for long time ventilation is the rise of technical possibilities. Bringing "intensive care" to the home of people challenges original understandings of home care. While intensive care and artificial respiration are technology-oriented, home-care is social-oriented, respecting the familiar environment of the patient. An international literature review reveals that research has been done by investigating the experiences of relatives and patients but not those of nurses. The few studies with a focus on nurses relate to themes of privacy and how to set limits. In Germany, not one study could be found that dealt with the question of how nurses experience artificial respiratory care in patients' homes. Considering the involved changes of care, the question rises, how nurses experience artificial respiratory care in the home of patients. This research is explorative and allows an insight into what home care is like when technology comes in. The exploration is based on eight narrative interviews with nurses who are experiencing respiratory care for patients in their home. The findings reveal professional challenges nurses have to face when caring for patients who are dependent on technological devices. The relatives are included in the caring activities and cooperating with them is crucial.

  6. Experience with the high-intensity sweetener saccharin impairs glucose homeostasis and GLP-1 release in rats.

    PubMed

    Swithers, Susan E; Laboy, Alycia F; Clark, Kiely; Cooper, Stephanie; Davidson, T L

    2012-07-15

    Previous work from our lab has demonstrated that experience with high-intensity sweeteners in rats leads to increased food intake, body weight gain and adiposity, along with diminished caloric compensation and decreased thermic effect of food. These changes may occur as a result of interfering with learned relations between the sweet taste of food and the caloric or nutritive consequences of consuming those foods. The present experiments determined whether experience with the high-intensity sweetener saccharin versus the caloric sweetener glucose affected blood glucose homeostasis. The results demonstrated that during oral glucose tolerance tests, blood glucose levels were more elevated in animals that had previously consumed the saccharin-sweetened supplements. In contrast, during glucose tolerance tests when a glucose solution was delivered directly into the stomach, no differences in blood glucose levels between the groups were observed. Differences in oral glucose tolerance responses were not accompanied by differences in insulin release; insulin release was similar in animals previously exposed to saccharin and those previously exposed to glucose. However, release of GLP-1 in response to an oral glucose tolerance test, but not to glucose tolerance tests delivered by gavage, was significantly lower in saccharin-exposed animals compared to glucose-exposed animals. Differences in both blood glucose and GLP-1 release in saccharin animals were rapid and transient, and suggest that one mechanism by which exposure to high-intensity sweeteners that interfere with a predictive relation between sweet tastes and calories may impair energy balance is by suppressing GLP-1 release, which could alter glucose homeostasis and reduce satiety.

  7. Experience with the high-intensity sweetener saccharin impairs glucose homeostasis and GLP-1 release in rats

    PubMed Central

    Swithers, Susan E.; Laboy, Alycia F.; Clark, Kiely; Cooper, Stephanie; Davidson, T.L.

    2012-01-01

    Previous work from our lab has demonstrated that experience with high-intensity sweeteners in rats leads to increased food intake, body weight gain and adiposity, along with diminished caloric compensation and decreased thermic effect of food. These changes may occur as a result of interfering with learned relations between the sweet taste of food and the caloric or nutritive consequences of consuming those foods. The present experiments determined whether experience with the high-intensity sweetener saccharin versus the caloric sweetener glucose affected blood glucose homeostasis. The results demonstrated that during oral glucose tolerance tests, blood glucose levels were more elevated in animals that had previously consumed the saccharin-sweetened supplements. In contrast, during glucose tolerance tests when a glucose solution was delivered directly into the stomach, no differences in blood glucose levels between the groups were observed. Differences in oral glucose tolerance responses were not accompanied by differences in insulin release; insulin release was similar in animals previously exposed to saccharin and those previously exposed to glucose. However, release of GLP-1 in response to an oral glucose tolerance test, but not to glucose tolerance tests delivered by gavage, was significantly lower in saccharin-exposed animals compared to glucose-exposed animals. Differences in both blood glucose and GLP-1 release in saccharin animals were rapid and transient, and suggest that one mechanism by which exposure to high-intensity sweeteners that interfere with a predictive relation between sweet tastes and calories may impair energy balance is by suppressing GLP-1 release, which could alter glucose homeostasis and reduce satiety. PMID:22561130

  8. Improving throughput and user experience for information intensive websites by applying HTTP compression technique.

    PubMed

    Malla, Ratnakar

    2008-11-06

    HTTP compression is a technique specified as part of the W3C HTTP 1.0 standard. It allows HTTP servers to take advantage of GZIP compression technology that is built into latest browsers. A brief survey of medical informatics websites show that compression is not enabled. With compression enabled, downloaded files sizes are reduced by more than 50% and typical transaction time is also reduced from 20 to 8 minutes, thus providing a better user experience.

  9. Fast six-channel pyrometer for warm-dense-matter experiments with intense heavy-ion beams

    SciTech Connect

    Ni, P.A.; Kulish, M.I.; Mintsev, V.; Nikolaev, D.N.; Ternovoi, V.Ya.; Hoffmann, D.H.H.; Udrea, S.; Tahir, N.A.; Varentsov, D.; Hug, A.

    2008-12-01

    This paper describes a fast multi-channel radiation pyrometer that was developed for warmdense-matter experiments with intense heavy ion beams at Gesellschaft fur Schwerionenforschung mbH (GSI). The pyrometer is capable of measuring of brightness temperatures from 2000 K to 50000 K, at 6 wavelengths in visible and near-infrared parts of spectrum, with 5 nanosecond temporal resolution and several micrometers spatial resolution. The pyrometer's spectral discrimination technique is based on interference filters, which act as filters and mirrors to allow for simultaneous spectral discrimination of the same ray at multiple wavelengths.

  10. Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Wilson, Rob; D'Arrigo, Rosanne; Andreu-Hayles, Laia; Oelkers, Rose; Wiles, Greg; Anchukaitis, Kevin; Davi, Nicole

    2017-08-01

    Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June-September, which may have implications for studying ocean-atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th-19th century temperatures ca. 0.5 °C cooler than the 20th-21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling

  11. Detector modules and spectrometers for the TIME-Pilot [CII] intensity mapping experiment

    NASA Astrophysics Data System (ADS)

    Hunacek, Jonathon; Bock, James; Bradford, C. Matt; Bumble, Bruce; Chang, Tzu-Ching; Cheng, Yun-Ting; Cooray, Asantha; Crites, Abigail; Hailey-Dunsheath, Steven; Gong, Yan; Li, Chao-Te; O'Brient, Roger; Shirokoff, Erik; Shiu, Corwin; Sun, Jason; Staniszewski, Zachary; Uzgil, Bade; Zemcov, Michael

    2016-07-01

    This proceeding presents the current TIME-Pilot instrument design and status with a focus on the close-packed modular detector arrays and spectrometers. Results of laboratory tests with prototype detectors and spectrometers are discussed. TIME-Pilot is a new mm-wavelength grating spectrometer array under development that will study the Epoch of Reionization (the period of time when the first stars and galaxies ionized the intergalactic medium) by mapping the fluctuations of the redshifted 157:7 μm emission line of singly ionized carbon ([CII]) from redshift z 5:2 to 8:5. As a tracer of star formation, the [CII] power spectrum can provide information on the sources driving reionization and complements 21 cm data (which traces neutral hydrogen in the intergalactic medium). Intensity mapping provides a measure of the mean [CII] intensity without the need to resolve and detect faint sources individually. We plan to target a 1 degree by 0.35 arcminute field on the sky and a spectral range of 199-305 GHz, producing a spatial-spectral slab which is 140 Mpc by 0.9 Mpc on-end and 1230 Mpc in the redshift direction. With careful removal of intermediate-redshift CO sources, we anticipate a detection of the halo-halo clustering term in the [CII] power spectrum consistent with current models for star formation history in 240 hours on the JCMT. TIME-Pilot will use two stacks of 16 parallel-plate waveguide spectrometers (one stack per polarization) with a resolving power R 100 and a spectral range of 183 to 326 GHz. The range is divided into 60 spectral channels, of which 16 at the band edges on each spectrometer serve as atmospheric monitors. The diffraction gratings are curved to produce a compact instrument, each focusing the diffracted light onto an output arc sampled by the 60 bolometers. The bolometers are built in buttable dies of 8 (low freqeuency) or 12 (high frequency) spectral channels by 8 spatial channels and are mated to the spectrometer stacks. Each detector

  12. The brain on art: intense aesthetic experience activates the default mode network

    PubMed Central

    Vessel, Edward A.; Starr, G. Gabrielle; Rubin, Nava

    2012-01-01

    Aesthetic responses to visual art comprise multiple types of experiences, from sensation and perception to emotion and self-reflection. Moreover, aesthetic experience is highly individual, with observers varying significantly in their responses to the same artwork. Combining fMRI and behavioral analysis of individual differences in aesthetic response, we identify two distinct patterns of neural activity exhibited by different sub-networks. Activity increased linearly with observers' ratings (4-level scale) in sensory (occipito-temporal) regions. Activity in the striatum (STR) also varied linearly with ratings, with below-baseline activations for low-rated artworks. In contrast, a network of frontal regions showed a step-like increase only for the most moving artworks (“4” ratings) and non-differential activity for all others. This included several regions belonging to the “default mode network” (DMN) previously associated with self-referential mentation. Our results suggest that aesthetic experience involves the integration of sensory and emotional reactions in a manner linked with their personal relevance. PMID:22529785

  13. LHC cryogenics – new experience of run with increased beam energy and intensity

    NASA Astrophysics Data System (ADS)

    Brodzinski, K.; Claudet, S.; Delikaris, D.; Delprat, L.; Ferlin, G.; Rogez, E.; Tavian, L.

    2017-03-01

    After the LHC first long shut down (LS1), when necessary consolidation and maintenance activities were performed on different technical systems, the Large Hadron Collider was progressively cooled down from ambient to operation temperatures from May of 2014. Prior to physics run with increased beam energy to 6.5 TeV/beam, increased beam intensity and modified beam injection scheme, several qualifications and tests affecting cryogenic system have been performed to ensure stable run of the accelerator. New beam parameters were gradually applied to the accelerator, reducing operational margins of cryogenic capacity from previous run. The process optimization and related updates in the control system were applied. This paper will briefly recall the main consolidations performed on the cryogenic system during LS1. The cool down process and behaviour of the cryogenic system during qualifications and tests will be presented. Difficulties and applied solutions during the run will be discussed. The availability and helium losses statistics for full year operation of 2015 will be given.

  14. High-intensity focused ultrasound for the treatment of solid tumor: Chinese clinical experience

    NASA Astrophysics Data System (ADS)

    Takeuchi, Akira; Zhang, Hong; Sun, Kun; Hasumura, Hiromi; Liu, Botao; Fu, Yurui; Yang, Zaocheng

    2006-05-01

    As a non-invasive modality, high-intensity focused ultrasound (HIFU) therapy has been received an interest for the treatment of solid tumor. There are some makers of HIFU for the equipment in China. The Sonic CZ901 is developed from the Mianyang stream that has a great advantage for guiding by color Doppler ultrasound imaging. For the research about possibility of this equipment, we evaluate the clinical usefulness to the solid tumor of HIFU treatment at Wujing general hospital in Beijing. We elucidate the result in 28 cases with benign and malignant tumor (Uterine myoma:16, Benign prostatic hypertrophy:5, Benign breast tumor:2, Breast cancer:1, Retroperitoneal tumor:1, Pheochromocytoma:1, Liver cancer: 2) . After 14˜90days, all cases show the reduction of tumor size (Max.3.2cm, Min.1.6cm, :Mean 2.2cm reduced), and the blood flow of tumor completely reduced in 7/23, partially reduced in16/23. Clinical symptoms disappeared in 7, clearly improved in 14, improved in 7. All treatments had no adverse event except for two cases of liver cancer. They felt an abdominal pain that controllable by medicine and it improved within 6hours. It is concluded that HIFU with guide by ultrasound imaging is very safe, painless and effective as the anti-tumor treatment.

  15. Severe Plasmodium falciparum malaria in the intensive care unit: A 6-year experience in Milano, Italy.

    PubMed

    Antinori, Spinello; Corona, Alberto; Castelli, Antonio; Rech, Roberto; Borghi, Beatrice; Giannotti, Claudia; Colombo, Riccardo; Fossali, Tommaso; Ballone, Elisabetta; Minari, Caterina; Perotti, Andrea; Bergomi, Paola; Galimberti, Laura; Milazzo, Laura; Ricaboni, Davide; Scorza, Daniele; Grande, Romualdo; Genderini, Francesco; Ieri, Marco; Raimondi, Ferdinando; Catena, Emanuele; Galli, Massimo; Corbellino, Mario

    Severe imported Plasmodium falciparum malaria is a potentially life-threatening disease with a reported mortality rate of 5-10% when patients are admitted to the Intensive Care Unit. To retrospectively review the clinical aspects, the value of severity predictive scores and the management of patients with severe P. falciparum malaria admitted to an ICU in Milano, Italy between January 2010 and December 2015. Twelve patients were included: seven were male and five female with a median age of 43 years. All were initially treated with intravenous quinine. Median parasitaemia upon admission was 14,5% (range 1-20%). At the time of ICU admission, 3 patients (25%) had 5 or more World Health Organization criteria for severe malaria while another 6 of them developed one or more of the latter during their stay in ICU. Five required mechanical ventilation because of respiratory failure due to ARDS. Four patients required renal replacement therapy. Three patients underwent blood exchange transfusion. All patients survived. Our retrospective evaluation of adults patients admitted to the ICU with severe imported P. falciparum malaria demonstrated a favourable outcome. Severity predictive scores currently in use probably overestimate the risk of malaria mortality in patients treated in health care systems of high income countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Early versus late tracheostomy in pediatric intensive care unit: does it matter? A 6-year experience.

    PubMed

    Pizza, Alessandro; Picconi, Enzo; Piastra, Marco; Genovese, Orazio; Biasucci, Daniele G; Conti, Giorgio

    2017-08-01

    The aim of this study is to examine the clinical data of children who underwent tracheostomy during their stay in Pediatric Intensive Care Unit (PICU), in order to describe the relationship between the timing of tracheostomy, the length of PICU stay and the occurrence of ventilator-associated pneumonia (VAP). This is a retrospective cohort study that collects all patients undergoing tracheostomy during their PICU stay over a six-year period. Data collection included PICU length of stay, days of intubation, days of mechanical ventilation, primary indication for tracheostomy, information about VAP and decannulations. The early tracheostomy group was defined as patients who had ten or fewer days of continuous ventilation, whereas the late tracheostomy group had more than ten days of continuous ventilation. A significant decrease in the rate of VAP incidence was noticed in the early tracheostomy group vs. late group (P=0.004, OR=0.39, 95% CI: 0.18-0.85). No differences were observed about decannulation, need of long-term ventilation and death rate. Significant decreases of days of mechanical ventilation and PICU stay were found in subgroup of patients who underwent early tracheostomy and were decannulated within 18 months. No standard timing for tracheostomy placement has been established in the pediatric population. Early tracheostomy can shorten the days of ventilation and hospitalization in PICU and reduce the incidence of VAP, but further studies are needed to identify patient categories in which it can be of benefit.

  17. Design and Fabrication of TES Detector Modules for the TIME-Pilot [CII] Intensity Mapping Experiment

    NASA Astrophysics Data System (ADS)

    Hunacek, J.; Bock, J.; Bradford, C. M.; Bumble, B.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Hailey-Dunsheath, S.; Gong, Y.; Kenyon, M.; Koch, P.; Li, C.-T.; O'Brient, R.; Shirokoff, E.; Shiu, C.; Staniszewski, Z.; Uzgil, B.; Zemcov, M.

    2016-08-01

    We are developing a series of close-packed modular detector arrays for TIME-Pilot, a new mm-wavelength grating spectrometer array that will map the intensity fluctuations of the redshifted 157.7 \\upmu m emission line of singly ionized carbon ([CII]) from redshift z ˜ 5 to 9. TIME-Pilot's two banks of 16 parallel-plate waveguide spectrometers (one bank per polarization) will have a spectral range of 183-326 GHz and a resolving power of R ˜ 100. The spectrometers use a curved diffraction grating to disperse and focus the light on a series of output arcs, each sampled by 60 transition edge sensor (TES) bolometers with gold micro-mesh absorbers. These low-noise detectors will be operated from a 250 mK base temperature and are designed to have a background-limited NEP of {˜ }10^{-17} mathrm {W}/mathrm {Hz}^{1/2}. This proceeding presents an overview of the detector design in the context of the TIME-Pilot instrument. Additionally, a prototype detector module produced at the Microdevices Laboratory at JPL is shown.

  18. Application of Phase Shifted, Laser Feedback Interferometry to Fluid Physics

    NASA Technical Reports Server (NTRS)

    Ovryn, Ben; Eppell, Steven J.; Andrews, James H.; Khaydarov, John

    1996-01-01

    We have combined the principles of phase-shifting interferometry (PSI) and laser-feedback interferometry (LFI) to produce a new instrument that can measure both optical path length (OPL) changes and discern sample reflectivity variations. In LFI, coherent feedback of the incident light either reflected directly from a surface or reflected after transmission through a region of interest will modulate the output intensity of the laser. LFI can yield a high signal-to-noise ratio even for low reflectivity samples. By combining PSI and LFI, we have produced a robust instrument, based upon a HeNe laser, with high dynamic range that can be used to measure either static (dc) or oscillatory changes along the optical path. As with other forms of interferometry, large changes in OPL require phase unwrapping. Conversely, small phase changes are limited by the fraction of a fringe that can be measured. We introduce the phase shifts with an electro-optic modulator (EOM) and use either the Carre or Hariharan algorithms to determine the phase and visibility. We have determined the accuracy and precision of our technique by measuring both the bending of a cantilevered piezoelectric bimorph and linear ramps to the EOM. Using PSI, sub-nanometer displacements can be measured. We have combined our interferometer with a commercial microscope and scanning piezoelectric stage and have measured the variation in OPL and visibility for drops of PDMS (silicone oil) on coated single crystal silicon. Our measurement of the static contact angle agrees with the value of 68 deg stated in the literature.

  19. Progress in electron- and ion-interferometry

    NASA Astrophysics Data System (ADS)

    Hasselbach, Franz

    2010-01-01

    In the 1970s the prominent goal was to overcome the limitations of electron microscopy caused by aberrations of electron lenses by the development of electron holography. In the meantime this problem has been solved, not only in the roundabout way of holography, but directly by correcting the aberrations of the lenses. Nevertheless, many quantitative electron microscopical measurement methods—e.g. mapping and visualization of electric and magnetic fields—were developed within the context of holography and have become fields of their own. In this review we focus on less popular electron interferometric experiments which complement the field of electron holography. The paper is organized as follows. After a short sketch of the development of electron biprism interferometry after its invention in 1954, recent advances in technology are discussed that made electron biprism interferometry an indispensable tool for solving fundamental and applied questions in physics: the development and preparation of conventional and single-atom field electron and field ion sources with their extraordinary properties. Single- and few-atom sources exhibit spectacular features: their brightness at 100 keV exceeds that of conventional field emitters by two orders in magnitude. Due to the extremely small aberrations of diode field emitter extraction optics, the virtual source size of single-atom tips is on the order of 0.2 nm. As a consequence it illuminates an area 7 cm in diameter on a screen at a distance of 15 cm coherently. Projection electron micrographs taken with these sources reach spatial resolutions of atomic dimensions and in-line holograms are—due to the absence of lenses with their aberrations—not blurred. Their reconstruction is straightforward. By addition of a carbon nanotube biprism into the beam path of a projection microscope a lensless electron interferometer has been realized. In extremely ultrahigh vacuum systems flicker noise is practically absent in the new

  20. Optical polarimetry for noninvasive glucose sensing enabled by Sagnac interferometry.

    PubMed

    Winkler, Amy M; Bonnema, Garret T; Barton, Jennifer K

    2011-06-10

    Optical polarimetry is used in pharmaceutical drug testing and quality control for saccharide-containing products (juice, honey). More recently, it has been proposed as a method for noninvasive glucose sensing for diabetic patients. Sagnac interferometry is commonly used in optical gyroscopes, measuring minute Doppler shifts resulting from mechanical rotation. In this work, we demonstrate that Sagnac interferometers are also sensitive to optical rotation, or the rotation of linearly polarized light, and are therefore useful in optical polarimetry. Results from simulation and experiment show that Sagnac interferometers are advantageous in optical polarimetry as they are insensitive to net linear birefringence and alignment of polarization components.

  1. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII)

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2012-01-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer to simultaneously obtain spatial and spectral information on science targets; the long baseline provides subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers.

  2. Modelling of a holographic interferometry based calorimeter for radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Beigzadeh, A. M.; Vaziri, M. R. Rashidian; Ziaie, F.

    2017-08-01

    In this research work, a model for predicting the behaviour of holographic interferometry based calorimeters for radiation dosimetry is introduced. Using this technique for radiation dosimetry via measuring the variations of refractive index due to energy deposition of radiation has several considerable advantages such as extreme sensitivity and ability of working without normally used temperature sensors that disturb the radiation field. We have shown that the results of our model are in good agreement with the experiments performed by other researchers under the same conditions. This model also reveals that these types of calorimeters have the additional and considerable merits of transforming the dose distribution to a set of discernible interference fringes.

  3. Application of digital phase-shift holographic interferometry to weak shock waves propagating at Mach 1.007

    NASA Astrophysics Data System (ADS)

    Mizukaki, Toshiharu

    2010-02-01

    Digital phase-shift holographic interferometry was applied to visualize weak shock waves and related phenomena quantitatively. This method of interferometry is an improved version of double-exposure holographic interferometry using digital image processing and a phase shift method. The obtained interferograms were analyzed using the Carré method. To evaluate the applicability of the interferometry to quantitatively visualize the phenomena, density profiles behind weak spherical shock waves generated with 500 μg of silver azide were examined. The results of the numerical analysis performed with the hydrocode AUTODYN were compared with those of the experiment. The Mach number of visualized shock waves was estimated to be 1.007 ± 0.001 at the pressure transducer near the test section. At the shock fronts, the density difference between the experimental and numerical results was within 0.3%.

  4. The Tromso Infant Faces Database (TIF): Development, Validation and Application to Assess Parenting Experience on Clarity and Intensity Ratings

    PubMed Central

    Maack, Jana K.; Bohne, Agnes; Nordahl, Dag; Livsdatter, Lina; Lindahl, Åsne A.W.; Øvervoll, Morten; Wang, Catharina E. A.; Pfuhl, Gerit

    2017-01-01

    Newborns and infants are highly depending on successfully communicating their needs; e.g., through crying and facial expressions. Although there is a growing interest in the mechanisms of and possible influences on the recognition of facial expressions in infants, heretofore there exists no validated database of emotional infant faces. In the present article we introduce a standardized and freely available face database containing Caucasian infant face images from 18 infants 4 to 12 months old. The development and validation of the Tromsø Infant Faces (TIF) database is presented in Study 1. Over 700 adults categorized the photographs by seven emotion categories (happy, sad, disgusted, angry, afraid, surprised, neutral) and rated intensity, clarity and their valance. In order to examine the relevance of TIF, we then present its first application in Study 2, investigating differences in emotion recognition across different stages of parenthood. We found a small gender effect in terms of women giving higher intensity and clarity ratings than men. Moreover, parents of young children rated the images as clearer than all the other groups, and parents rated “neutral” expressions as more clearly and more intense. Our results suggest that caretaking experience provides an implicit advantage in the processing of emotional expressions in infant faces, especially for the more difficult, ambiguous expressions. PMID:28392772

  5. The Tromso Infant Faces Database (TIF): Development, Validation and Application to Assess Parenting Experience on Clarity and Intensity Ratings.

    PubMed

    Maack, Jana K; Bohne, Agnes; Nordahl, Dag; Livsdatter, Lina; Lindahl, Åsne A W; Øvervoll, Morten; Wang, Catharina E A; Pfuhl, Gerit

    2017-01-01

    Newborns and infants are highly depending on successfully communicating their needs; e.g., through crying and facial expressions. Although there is a growing interest in the mechanisms of and possible influences on the recognition of facial expressions in infants, heretofore there exists no validated database of emotional infant faces. In the present article we introduce a standardized and freely available face database containing Caucasian infant face images from 18 infants 4 to 12 months old. The development and validation of the Tromsø Infant Faces (TIF) database is presented in Study 1. Over 700 adults categorized the photographs by seven emotion categories (happy, sad, disgusted, angry, afraid, surprised, neutral) and rated intensity, clarity and their valance. In order to examine the relevance of TIF, we then present its first application in Study 2, investigating differences in emotion recognition across different stages of parenthood. We found a small gender effect in terms of women giving higher intensity and clarity ratings than men. Moreover, parents of young children rated the images as clearer than all the other groups, and parents rated "neutral" expressions as more clearly and more intense. Our results suggest that caretaking experience provides an implicit advantage in the processing of emotional expressions in infant faces, especially for the more difficult, ambiguous expressions.

  6. Contrast and Intensity upgrades to the Texas Petawatt laser for hadron generation and non-linear QED experiments

    NASA Astrophysics Data System (ADS)

    Hegelich, Bjorn M.; Arefiev, Alexey; Ditmire, Todd; Donovan, Michael E.; Dyer, Gillis; Gaul, Erhard; Labun, Lance; Luedtke, Scott; Martinez, Mikael; McCarry, Edward; Stark, David; Pomerantz, Ishay; Tiwari, Ganesh; Toncian, Toma

    2015-11-01

    Advances in laser-based hadron generation, especially with respect to particle energy, as well as reaching the new regime of radiation dominated plasmas and non-linear QED, require laser fields of Petavolts per meter that preferably interact with very high density, overcritical plasmas. To achieve these conditions we are upgrading the Texas Petawatt Laser both respect to on-target laser intensity and laser-contrast, aiming to reach intensities of ~ 5x1022 W/cm2 and pulse contrast parameters allowing the interaction with overcritical, yet ultrathin, sub-micron targets. We will report on the planned experiments aimed at ion acceleration, neutron generation and the first experimental measurement of radiation reactions to motivate the chosen upgrade parameters. We will further report on the technical changes to the laser and present first measurements of the achieved intensity and contrast parameters. This work was supported by NNSA cooperative agreement DE-NA0002008, the Defense Advanced Research Projects Agency's PULSE program (12-63-PULSE-FP014), the Air Force Office of Scientific Research (FA9550-14-1-0045) and the National Institute of Health SBIR.

  7. Dose Intensity in Early-Stage Breast Cancer: A Community Practice Experience

    PubMed Central

    Bretzel, Robert L.; Cameron, Ralph; Gustas, Marc; Garcia, Maria A.; Hoffman, Heather K.; Malhotra, Rosalind; Miller, Karen; Prime, Janine; Favret, Anne

    2009-01-01

    Purpose: This retrospective study was a quality initiative to determine practice patterns in adjuvant chemotherapy for early-stage breast cancer (ESBC) and define the incidence and causative factors of suboptimal relative dose intensity (RDI). Our community-based practice participates in ASCO's Quality Oncology Practice Initiative in an effort to improve the quality of care provided to our patients. Most metrics do not have a direct proven correlation with improvement in survival, but measurement of RDI does. Patients and Methods: Our study was a retrospective analysis of patients with ESBC. Each patient was treated on an outpatient basis in a community practice setting. We used the diagnosis criteria of breast cancer to create a list of eligible patients within the data range from our electronic medical record. Inclusion criteria consisted of all women seen in our offices receiving adjuvant chemotherapy for a diagnosis of breast cancer. Exclusion criteria included patients with metastatic disease and patients not receiving chemotherapy. Results: The average weighted RDI for all patients was 98.4%. Of the 834 evaluable patients we reviewed, 102 patients (12.2%) had some reduction in RDI. This subset had an average RDI of 88%. Twenty-nine patients (3.5%) had an RDI of less than 85%. Conclusion: Because decreased RDI has been shown to correlate with decreased overall and disease-free survival rates, we were compelled to measure and determine causative factors in our patients with ESBC. The primary reasons for dose delay and overall reduction in RDI were scheduling and neutropenia. Scheduling delays were initiated by both patients and medical staff, with the majority requested by patients. PMID:21479074

  8. Experience with position-sensitive neutron detectors at the Intense Pulsed Neutron Source

    NASA Astrophysics Data System (ADS)

    Crawford, R. K.; Haumann, J. R.; Epperson, J. E.; Thiyagarajan, P.; Schultz, A. J.; Felcher, G. P.; Montague, D. G.; Dejus, R. J.

    1990-12-01

    At the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory, pulses of protons accelerated in a synchrotron produce pulses of fast neutrons via the spallation process in an enriched uranium target. After moderation, the resulting pulses of slow neutrons are directed into beams which serve a variety of neutron-scattering instruments. Currently there are thirteen neutron-scattering instruments in operation or under development at IPNS, and six of these use position-sensitive neutron detectors (PSDs). These PSDs are: a 30 cm × 30 cm, ˜3 mm resolution, neutron Anger camera area PSD with 6Li-glass scintillator; a 2.5 cm diameter, ˜0.7 mm resolution, microchannel-plate area PSD with 6Li-glass scintillator; a 20 cm × 20 cm, ˜5 mm resolution, 3He proportional-counter area PSD; a 40 cm × 40 cm, ˜4 mm resolution, 3He proportional-counter area PSD; a flat 20 cm long, ˜1.6 mm resolution, 3He proportional-counter linear PSD; and 160 cylindrical 3He proportional-counter linear PSDs, each of which is 1.27 cm in diameter and 60 cm long and has ˜14 mm resolution. These detectors, in addition to being position-sensitive, resolve the time of the neutron capture with ˜1 μs precision for neutron time-of-flight measurements. This paper will discuss these various PSDs with emphasis on the instrumental specifications and the reasons for the selection of the different types of PSDs, and will also discuss the observed performances of these PSDs.

  9. Experience with position sensitive neutron detectors at the Intense Pulsed Neutron Source

    SciTech Connect

    Crawford, R.K.; Haumann, J.R.; Schultz, A.J.; Felcher, G.P.; Epperson, J.E.; Thiyagarajan, P.; Montague, D.G.; Dejus, R.J.

    1990-05-07

    At the Intense Pulsed Neutron Source (IPNS) pulses of protons accelerated in a synchrotron produce pulses of fast neutrons via the spallation process in an enriched uranium target. After moderation, the resulting pulses of slow neutrons are directed into beams which serve a variety of neutron scattering instruments. Currently there are thirteen neutron scattering instruments in operation or under development at IPNS, and six of these use position-sensitive neutron detectors (PSDs). These PSDs are: a 30 cm {times} 30 cm, {approximately}3 mm resolution, neutron Anger camera area PSD with {sup 6}Li-glass scintillator; a 2.5 cm dia, {approximately}0.7 mm resolution, microchannel-plate area PSD with {sup 6}Li-glass scintillator; a 20 cm {times} 20 cm, {approximately}5 mm resolution, {sup 3}He proportional counter area PSD; a 40 cm {times} 40 cm, {approximately}4 mm resolution, {sup 3}He proportional counter area PSD; a flat 20 cm long, {approximately}1.6 mm resolution, {sup 3}He proportional counter linear PSD; and 160 cylindrical {sup 3}He proportional counter linear PSDs, each of which is 1.27 cm in dia 60 cm long and has {approximately}14 mm resolution. These detectors, in addition to being position-sensitive, resolve the time of the neutron capture with {approximately}1 {mu}s precision for neutron time-of-flight measurements. This paper will discuss these various PSDs with emphasis on the instrumental specifications and the reasons for the selection of the different types of PSDs, and will also discuss the observed performances of these PSDs. 14 refs., 6 figs., 1 tab.

  10. Telemedicine as a tool for intensive management of diabetes: the DIABTel experience.

    PubMed

    Gómez, E J; Hernando, M E; García, A; Del Pozo, F; Cermeño, J; Corcoy, R; Brugués, E; De Leiva, A

    2002-08-01

    This paper presents the current features of the DIABTel telemedicine system and the evaluation outcomes of its use in clinical routine. This telemedicine system is designed to complement the daily care and intensive management of diabetic patients through telemonitoring and telecare services. The system comprises a patient unit (PU) used by patients in their day-to-day activities and a Medical Workstation used by physicians and nurses at hospitals. Both applications offer tools to collect, manage, view and interpret data and to exchange data and messages. The system was evaluated for usability, telemedical protocols, metabolic control and quality of life. This evaluation consisted in a 6-month cross-over pilot study with ten Type I diabetic patients. The results of the evaluation allowed assessment of the telemedicine protocols in terms of the number of communications/patient (21.6+/-7.7); days between communications (5.4+/-2.66); messages sent by physicians (118 text messages); and data and messages transmitted by patients (3524 blood glucose readings, 1649 day-to-day insulin adjustments, 24 exercise reports, ten diet modifications and 63 text messages). Physicians performed more therapeutic changes during the DIABTel period than in the control period. There was a trend towards HbA1c improvement during DIABTel use with no incidence in the number of hypoglycaemias. This pilot study demonstrates the feasibility of the DIABTel system in clinical routine use and its potential benefits for diabetes care: improving the availability of information necessary for therapy adjustments; offering new physician-patient communication tools; increasing patient empowerment and education; and showing a positive trend towards improving the metabolic control of patients. Further studies are needed to validate these findings and to promote telemedicine as an opportunity to better diabetes care.

  11. Hair removal using intense pulsed light (EpiLight): patient satisfaction, our experience, and literature review.

    PubMed

    Fodor, Lucian; Menachem, Meital; Ramon, Ytzhack; Shoshani, Oren; Rissin, Yaron; Eldor, Liron; Egozi, Dana; Peled, Isaac J; Ullmann, Yehuda

    2005-01-01

    Applications for intense pulsed light (IPL) for hair removal are gaining favor among other methods, including lasers, because of its noninvasive nature, versatility regarding different skin and hair types, safety, and ease of use. Hair removal using IPL was performed from January 2002 to December 2003 on 108 consecutive patients. Eighty of these patients answered a questionnaire and were enrolled in the study group. The investigated parameters were hair and skin type, number of pulses, fluence, pulse duration, pulse delay, the filters used, and the treated area. The patient assessment of improvement (satisfaction) rate was graded from 1 to 5 points: 1, worse; 2, no improvement; 3, mild improvement; 4, good result; and 5, excellent result. The patients had between 1 and 13 treatments most of them during 2 to 6 sessions. Sixty-seven percent of the patients reported no complications. Prolonged erythema for more than 7 days was reported by 16.25%, blisters by 6.25%, temporary hyperpigmentation by 8.75%, leukotrichia was present in 1 case, and 1 case of persistent hypopigmentation was noted in a young girl. An increased number of complications and a decreased satisfaction rate were noted with higher skin types, but it was not statistically significant. Patients who underwent fewer treatments (1-3 treatments) were more satisfied compared with those who had more than 7 treatments (P < 0.02). Sixty percent of the patients rated their satisfaction to be good to excellent and 65% would ill recommend this treatment to their friends. To minimize the complication rate the authors found that the preset parameters should be adjusted at every treatment session according to the skin response at the previous one. Permanent hair removal cannot be guaranteed and it is not possible to predict the improvement rate. Nevertheless, based on patient satisfaction rate in this study, the authors recommend using IPL for hair removal.

  12. Initial experience with a radiology imaging network to newborn and intensive care units.

    PubMed

    Witt, R M; Cohen, M D; Appledorn, C R

    1991-02-01

    A digital image network has been installed in the James Whitcomb Riley Hospital for Children on the Indiana University Medical Center to create a limited all digital imaging system. The system is composed of commercial components, Philips/AT&T CommView system, (Philips Medical Systems, Shelton, CT; AT&T Bell Laboratories, West Long Beach, NJ) and connects an existing Philips Computed Radiology (PCR) system to two remote workstations that reside in the intensive care unit and the newborn nursery. The purpose of the system is to display images obtained from the PCR system on the remote workstations for direct viewing by referring clinicians, and to reduce many of their visits to the radiology reading room three floors away. The design criteria includes the ability to centrally control all image management functions on the remote workstations to relieve the clinicians from any image management tasks except for recalling patient images. The principal components of the system are the Philips PCR system, the acquisition module (AM), and the PCR interface to the Data Management Module (DMM). Connected to the DMM are an Enhanced Graphics Display Workstation (EGDW), an optical disk drive, and a network gateway to an ethernet link. The ethernet network is the connection to the two Results Viewing Stations (RVS) and both RVSs are approximately 100 m from the gateway. The DMM acts as an image file server and an image archive device. The DMM manages the image data base and can load images to the EGDW and the two RVSs. The system has met the initial design specifications and can successfully capture images from the PCR and direct them to the RVSs.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Aichi Cancer Center Initial Experience of Intensity Modulated Radiation Therapy for Nasopharyngeal Cancer Using Helical Tomotherapy

    SciTech Connect

    Kodaira, Takeshi Tomita, Natsuo; Tachibana, Hiroyuki; Nakamura, Tatsuya; Nakahara, Rie; Inokuchi, Haruo; Fuwa, Nobukazu

    2009-03-15

    Purpose: To assess the feasibility of helical tomotherapy (HT) for patients with nasopharyngeal carcinoma. Methods and Materials: From June 2006 to June 2007, 20 patients with nasopharyngeal carcinoma were treated with HT with (n = 18) or without (n = 2) systemic chemotherapy. The primary tumor and involved lymph node (PTV1) were prescribed 70 Gy and the prophylactic region 54 Gy at D95, respectively. The majority of patients received 2 Gy per fraction for PTV1 in 35 fractions. Parotid function was evaluated using quantitative scintigraphy at pretreatment, and posttreatment at 3 months and 1 year later. Results: The median patient age was 53 years, ranging from 15 to 83. Our cohort included 5, 8, 4, 2, and 1 patients with disease Stages IIB, III, IVA, IVB, and IVC, respectively. Histopathological record revealed two for World Health Organization Type I and 18 for Type 2 or 3. The median duration time for treatment preparation was 9.5 days, and all plans were thought to be acceptable regarding dose constraints of both the planning target volume and organ at risk. All patients completed their treatment procedure of intensity-modulated radiation therapy (IMRT). All patients achieved clinical remission after IMRT. The majority of patients had Grade 3 or higher toxicity of skin, mucosa, and neutropenia. At the median follow-up of 10.9 months, two patients recurred, and one patient died from cardiac disease. Parotid gland function at 1 year after completion of IMRT was significantly improved compared with that at 3 months. Conclusion: HT was clinically effective in terms of IMRT planning and utility for patients with nasopharyngeal cancer.

  14. The experiences of parents with infants in Neonatal Intensive Care Unit.

    PubMed

    Heidari, Haydeh; Hasanpour, Marzieh; Fooladi, Marjan

    2013-05-01

    In recent years significant medical science advances have been made in the field midwifery and infant care. The premature, low birth weight and ill infants are admitted to the technologically advanced NICU for care and they often require long-term stay. This study addresses parental experiences with the infant care in NICU, explores their concerns regarding nursing supports for parents and offers nurses' perspectives on performing duties. A qualitative inductive content analysis method was applied in 2011 that included a purposely selected group of parents, nurses and physicians from neonatal unit at the Medical Science University of Isfahan. Participants were surveyed and interviewed according to the institutional ethics committee approval and signed informed consents. THE CONTENT ANALYSIS IDENTIFIED TWO MAIN CATEGORIES: 1) the definition of stress, which consisted of misgivings, nervous pressure, imbalance, separation and 2) the parents' reaction to stress, which revealed emotional, psychotic and behavioral reactions as subcategories. The medical team awareness of NICU parent experiences is essential to the quality of care. Recognizing the type of parents' reaction to the whole process by the healthcare team seems essential to the optimum outcome.

  15. Computer-intensive simulation of solid-state NMR experiments using SIMPSON

    NASA Astrophysics Data System (ADS)

    Tošner, Zdeněk; Andersen, Rasmus; Stevensson, Baltzar; Edén, Mattias; Nielsen, Niels Chr.; Vosegaard, Thomas

    2014-09-01

    Conducting large-scale solid-state NMR simulations requires fast computer software potentially in combination with efficient computational resources to complete within a reasonable time frame. Such simulations may involve large spin systems, multiple-parameter fitting of experimental spectra, or multiple-pulse experiment design using parameter scan, non-linear optimization, or optimal control procedures. To efficiently accommodate such simulations, we here present an improved version of the widely distributed open-source SIMPSON NMR simulation software package adapted to contemporary high performance hardware setups. The software is optimized for fast performance on standard stand-alone computers, multi-core processors, and large clusters of identical nodes. We describe the novel features for fast computation including internal matrix manipulations, propagator setups and acquisition strategies. For efficient calculation of powder averages, we implemented interpolation method of Alderman, Solum, and Grant, as well as recently introduced fast Wigner transform interpolation technique. The potential of the optimal control toolbox is greatly enhanced by higher precision gradients in combination with the efficient optimization algorithm known as limited memory Broyden-Fletcher-Goldfarb-Shanno. In addition, advanced parallelization can be used in all types of calculations, providing significant time reductions. SIMPSON is thus reflecting current knowledge in the field of numerical simulations of solid-state NMR experiments. The efficiency and novel features are demonstrated on the representative simulations.

  16. Survey of Canadian critical care nurses' experiences of conflict in intensive care units.

    PubMed

    Edwards, Marie; Throndson, Karen; Girardin, Julie

    2012-01-01

    The purpose of this study was to enhance our understanding of Canadian critical care nurses' experiences of and responses to situations of conflict in the ICU. Through a 35-item web-based survey, members of the Canadian Association of Critical Care Nurses were asked questions regarding the types, causes and frequency of conflict experienced, the nursing interventions found most helpful in situations of conflict, and the resources found most helpful in responding to situations of conflict. A total of 241 nurses responded to the survey. The mean age of the nurses was 43 years, and the majority were female (89.2%), direct care providers (66.4%), with greater than 11 years of experience in critical care (58.3%), and working in medical/surgical ICUs (66.4%) in tertiary care hospitals (67.2%). Approximately 51% of the nurses reported being involved in at least one situation of conflict related to the management of a patient in the last week worked. The most common types of conflict encountered were disagreements between the team and family (46.5%) or within the team (35.3%). The nurses acknowledged the importance of clear, consistent and honest communication with patients and families when conflict arises and rank-ordered the resources found most helpful to patients, families, and nurses in conflict situations. Implications for practice and education are discussed and recommendations for future research are outlined.

  17. Computer-intensive simulation of solid-state NMR experiments using SIMPSON.

    PubMed

    Tošner, Zdeněk; Andersen, Rasmus; Stevensson, Baltzar; Edén, Mattias; Nielsen, Niels Chr; Vosegaard, Thomas

    2014-09-01

    Conducting large-scale solid-state NMR simulations requires fast computer software potentially in combination with efficient computational resources to complete within a reasonable time frame. Such simulations may involve large spin systems, multiple-parameter fitting of experimental spectra, or multiple-pulse experiment design using parameter scan, non-linear optimization, or optimal control procedures. To efficiently accommodate such simulations, we here present an improved version of the widely distributed open-source SIMPSON NMR simulation software package adapted to contemporary high performance hardware setups. The software is optimized for fast performance on standard stand-alone computers, multi-core processors, and large clusters of identical nodes. We describe the novel features for fast computation including internal matrix manipulations, propagator setups and acquisition strategies. For efficient calculation of powder averages, we implemented interpolation method of Alderman, Solum, and Grant, as well as recently introduced fast Wigner transform interpolation technique. The potential of the optimal control toolbox is greatly enhanced by higher precision gradients in combination with the efficient optimization algorithm known as limited memory Broyden-Fletcher-Goldfarb-Shanno. In addition, advanced parallelization can be used in all types of calculations, providing significant time reductions. SIMPSON is thus reflecting current knowledge in the field of numerical simulations of solid-state NMR experiments. The efficiency and novel features are demonstrated on the representative simulations.

  18. Tunable-optical-filter-based white-light interferometry for sensing.

    PubMed

    Yu, Bing; Wang, Anbo; Pickrell, Gary; Xu, Juncheng

    2005-06-15

    We describe tunable-optical-filter-based white-light interferometry for sensor interrogation. By introducing a tunable optical filter into a white-light interferometry system, one can interrogate an interferometer with either quadrature demodulation or spectral-domain detection at low cost. To demonstrate the feasibility of effectively demodulating various types of interferometric sensor, experiments have been performed using an extrinsic Fabry-Perot tunable filter to interrogate two extrinsic Fabry-Perot interferometric temperature sensors and a diaphragm-based pressure sensor.

  19. Stitching interferometry of aspherical surfaces

    NASA Astrophysics Data System (ADS)

    Haensel, Thomas; Nickel, Andreas; Schindler, Axel

    2001-12-01

    Sub-aperture stitching interferometry (SASI) is an appropriate method to measure either large optical plane surface topologies or aspheres with strong deviation from the flatness with standard interferometers. Using SASI the surface shape is measured with a higher lateral resolution by multiple adjacent sub-aperture measurements with a sufficient overlap of the neighboring areas. In a second step, the total surface shape is composed with the help of a computer code by stitching the sub-aperture areas together. The overlap areas allow fitting. By means of a regression analysis, tilt and vertical displacement of adjacent areas are calculated and minimized. A confidence band calculated using a MATLAB based code describes the accuracy of the composition. The variance of this estimation is inverse proportional to the peak to valley value (PV) of the measured area and decreases with a 10-3 scaling of the width of the overlapping area. A statistical experimental design method is used to minimize the number of sub-apertures to be measured. The accuracy of the stitched total surface measurement can be increased with the help of model calculations by optimizing (i) the position of the sub-aperture, which was regarded as a standard, and (ii) the sequence of the stitched adjacent areas.

  20. Precision optical interferometry in space

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    POINTS, an astrometric Optical interferometer with a nominal measurement accuracy of 5 microarcseconds for the angle between a pair of stars separated by about 90 deg, is presently under consideration by two divisions of NASA-OSSA. It will be a powerful new multi-disciplinary tool for astronomical research. If chosen as the TOPS-1 (Toward Other Planetary Systems) instrument by the Solar-System Exploration Division, it will perform a definitive search for extra-solar planetary systems, either finding and characterizing a large number of them or showing that they are far less numerous than now believed. If chosen as the AIM (Astrometric Interferometry Mission) by the Astrophysics Division, POINTS will open new areas of astrophysical research and change the nature of the questions being asked in some old areas. In either case. it will be the first of a new class of powerful instruments in space and will prove the technology for the larger members of that class to follow. Based on a preliminary indication of the observational needs of the two missions, we find that a single POINTS mission will meet the science objectives of both TOPS-1 and AIM. The instrument detects dispersed fringe (channel led spectrum) and therefore can tolerate large pointing errors.